HunterT your goal of 300hp out of a 305 chevy is possible.I have pulled 328hp out of one that was bored .030 over and had a 9.5:1cr for a friend.We used a .458 lunati cam kit and port match intake and heads. ported intake and exhuast ports as well heads had 1.84/1.50 valves with a 3angle valve job.I recomend 1-5/8" headers and dual 2-1/2" exhuast. For intake we used a torker2 and top of with a holley 450cfm carburetor hope this helps  

Pontiac_SS:
The only suggestion i can make considering my limited abilitys and knowledge on performance is to do what my cousin did, Put 350 heads,Intake, And Cam on your 305 and top it off with an elderbrock 650cfm Carb, it seems to work pretty well for his monte carlo

And the good news is the same top end could be transfered over to another SBC Chevy so no money lost if you go for a serious upgrade.  My friend did this with his Camaro, then when he finally got a short block together with a 383 stroker bottom end he swapped it all over.    

See the 305 can make 300hp. From 250hp factory.You only need to find 50 extra horses.Remember you only need 6.5hp extra per cylinder.Heck,even a port job with the standard cam might surprise you. You don't need a solid cam or 12:1 compression,as radical cams (like for a bigblock) require radical compression,to idle and operate effectively to make big block power;like 16:1.Yeah these small blocks make 900+hp! Probably cost 30+grand to build one.They are based on rpms and not street torque. The shorter stroke is alot less stressful on the crank.In 1970 keith Black had a de-stroked 340LA producing 500hp from 305cubes!..............................THE REAL SECRET! your car engine only has to produce enough torque to overcome its own weight and wind resistance for a given speed. THat is if you want your car to run 14sec quarters, say at 110mph,you build your motor with a realistic torque level and a couple thousand rpms beyond that. Many rev heads build engines with way too much power and torque,yeah they burn rubber while you shoot off in the distance............Personally I like good low down torque and instant throttle response,in most cases its what wins races on the street,with a 6,500 to 7,000 red line and 220 to 230deg hydralic will get you there @.050.  

powerdreams:
See the 305 can make 300hp. From 250hp factory.You only need to find 50 extra horses.Remember you only need 6.5hp extra per cylinder.Heck,even a port job with the standard cam might surprise you. You don't need a solid cam or 12:1 compression,as radical cams (like for a bigblock) require radical compression,to idle and operate effectively to make big block power;like 16:1.Yeah these small blocks make 900+hp! Probably cost 30+grand to build one.They are based on rpms and not street torque. The shorter stroke is alot less stressful on the crank.In 1970 keith Black had a de-stroked 340LA producing 500hp from 305cubes!..............................THE REAL SECRET! your car engine only has to produce enough torque to overcome its own weight and wind resistance for a given speed. THat is if you want your car to run 14sec quarters, say at 110mph,you build your motor with a realistic torque level and a couple thousand rpms beyond that. Many rev heads build engines with way too much power and torque,yeah they burn rubber while you shoot off in the distance............Personally I like good low down torque and instant throttle response,in most cases its what wins races on the street,with a 6,500 to 7,000 red line and 220 to 230deg hydralic will get you there @.050.

LMAO...forgive me...as an Olds guy I find it absolutely hysterical that you consider a 7000 RPM 305 to have "good low down torque"...   For that matter a 7000 RPM anything having good low down torque...

And what does the keith black de-stroked 340 have to do with this conversation...since it was a short stroke, big bore engine (4.04" bore)??  Have you forgotten that the 305 is the exact opposite...long stroke, small bore engine??

No one has been arguing that the 305 cant make 300 HP...its that it actually takes WORK to make it.  Point is you'll make more power with less work and less money with any SBC having a bigger bore.

Is the original poster paying attention anymore??  

The 340 was a reference to another comment about desroking motors.I'm glad that you agree,that it can make 300hp. and 7,000rpm.Next time I'm down your way,find me a willing participant with a 305 built to my specs and I'll show you ,if a GM tach goes that far? that it'll have excellent torque down low and I'll make the needle hit 7g's.Shotpeened rods and crank with ARP fasteners throughout..............A 340 is a far superior engine,I was talking in terms of cubes. A 305 can do it,after all it is a car engine regardless of stroke.The rod ratio is important.There are many sb and bb strokers that see 8,000plus rpm!  

powerdreams:
The 340 was a reference to another comment about desroking motors.I'm glad that you agree,that it can make 300hp. and 7,000rpm.Next time I'm down your way,find me a willing participant with a 305 built to my specs and I'll show you ,if a GM tach goes that far? that it'll have excellent torque down low and I'll make the needle hit 7g's.Shotpeened rods and crank with ARP fasteners throughout..............A 340 is a far superior engine,I was talking in terms of cubes. A 305 can do it,after all it is a car engine regardless of stroke.The rod ratio is important.There are many sb and bb strokers that see 8,000plus rpm!

Uh...no one has argued that the cubes can't support power...its the bore.  This has nothing to do with ANYTHING except the bore.  Its tiny.  It can't support large enough valves, and thus, not enough cylinder head flow to make power like a 302 SBC can...like a 327 SBC can...like a 350, 383, 400, 427, 454 SBC can.  And they are all in the same physical package...so why waste time with such a worthless engine?  It takes WORK to make 300 HP...it doesn't with a 350...heck it doesn't take much work to make it with a 302.

Small bore = valve shrouding.  Valve shrouding = horrible flow...ever wonder why the Hemi was such a success???  It has the same displacement as a number of other engines of the era...but it has virtually no valve shrouding...hence...DOMINANCE.  Air flow through a hemi design is unrivaled...because nothing gets in the way of air flowing around those massive valves.

And apparently you missed the "Olds guy" part of the torque comment...no 305...without the help of a MASSIVE roots type blower will ever come close to the low end torque a big block Olds puts out.  ARP fasteners aren't going to help you make torque...neither are shotpeened rods and a crank.  I have the ultimate torque "monster" 305...it has TPI (the absolute best induction system for low RPM torque...though its one of the worst for high RPM power), 9.6:1 compression, 3 angle valve job, port matched intake to the heads, small small cam, headers, high flow cat, and an $800 Borla adjustable cat back exhaust.  It won't touch my 350 Olds in torque...much less my stock 425 or any 455.  Makes less power too...so in all...there is nothing that engine is good at...it even gets the same gas mileage as my 400HP 350 Olds powered Cutlass (20 mpg on the highway).

So again...what is the point?  To be different?  It looks the same as any old 350 Chevy.  Cuz you're on a budget?  So you're gonna dump money into something that wont respond until you upgrade the cam, intake, carb, heads, and exhaust...seems like saving up for a crate 350 would be a better choice (sure wish I had figured that out!).  To keep it numbers matching?  It'll be worth more money if its unmolested and numbers matching.  So can anyone tell me one good reason to put money into a 305?  About the only one is "because I can"...in which case have fun...  

Chevy crate engines in my opinion suck a buddy of mine bought the 355hp 350 with aluminum heads and it ran like it had 255hp. A waste of money just my opinion  

Well said pontiacman! Most crate engine buyers are impressed by near or 400hp numbers.Then once running they wish they bought the 300/320hp version........................CSIROC to put bigger valves in a smaller bore is only a matter of how far you can notch the top of the cylinder bore.Before you go criticising small valves..............An experiment motor a 360la with a mild cam and factory 318la heads.This thing was making power till the engine would blow up from over revving.It pulled strong from idle to well over 8,000rpm in a car 3,300lbs.We found the engine was making the same power as the larger heads only at a much higher rpm.............On the road it felt like a rocket,low down torque was tyre frying awesome!Rev range and rpm limit was far more versatile than with the bigger heads and valves.The key? with smaller valves and port sizes the cubes are seeking to produce optimum power at a higher rpm ,to achieve enough air flow vs amount of fuel..............With gears from 3.7 to 4.1 ET's are very impressive!why? because your changing at 7,500 instead of 6,500(larger heads) which means more mph through the gears regardless of power numbers!of course the cam and all other components identical except for the heads...........And a side bonus the smaller heads were more economical.......In order for the larger heads the have the same rpm ability requires more cam and compression and fuel,yes they make more power!so what!..................A street race about a year ago two identical GM bodied cars from 1969 ,both in very good codition.One a tq20 erson cam 253CI,2,200high stall and 3.36 LSD,3spd auto....The other was a 350CHEV! Lumpy DEEEEEP note cam!turbo 400 auto and dont know diff or high stall,but twin 2 1/2" exhaust pipes. the 253 single 3".......From a rolling start. WE the 253GM pulled along side our 350GM comarade.Gave a nod and smile,then.......................drum roll please! WE both nailed it.We BLEW HIS DOORS OFF BIG TIME! and he knew it.Thoroughly humiliated with alot less cubes.His big cam takes longer to enter its power band range.Ours starts at 20mph his at 60mph. On the street,small valves and heads can and do work,with the right combination of parts.  

It's clear that you don't understand the concepts we're speaking of here, so why don't you stop trying so hard to push your ideas. We aren't going to agree with completely backwards information just because you think some street car benefited from it.

"CSIROC" more than myself, but we gather our information a little more scientifically than blowing the doors off of local street cars. We aren't going to bow down to you as and say that everything you speak of is the absolute truth...  

How safe is it to run a 305 up to 8,000 rpm?  Especially when it is stock.  Wouldn't you have to invest alot of money in the short block to rev it that high?  I always heard that for a motor you want to rev up you should have a short stroke and for a motor with alot of low end torque you should have a motor with a long stroke.  

Firstly I'm not suggesting that you run any engine to 8,000rpm on a continual basis.And that quote specifically was related to an experimental motor.I totally agree if a motor is going to see 8,000rpm regularly,it has to be built to take it.However,if you have a well balanced,lightened and strong bottom end and a valve train to take it,the occaisional visit to 7,000 is totally possible.........Gib,How are ya buddy?I see you've returned from rehab.I speak from truth and experience.You seem to have an emphasis (engine wise)on power and touque dyno numbers,which are always great and impressive...............How these numbers are related to effectiveness and dynamic engine performance on the STREET is my point....................You can curse and condescend my opinions,but I've experienced many V8's and their owners opinions.They range from all out drag cars to daily drivers.Readers are free in this forum to regard or disregard information.....................My threads relate to STREET and not Fully set up drag cars that can cut 9sec ET's with 500hp.My ideas are shared by many in the performance world..............................It's funny, I read about a crate 360 Chrysler ,producing 390 plus hp, big valves and runners and single plane intake,with a holley 750cfm. The cam 240deg duration at .050" and .510" lift (way too much duration!).............Anyway installed in a duster with 3.9:1,auto and 2,500 high stall it ran 12.9sec ET impressive..................In that same issue was a home built 360 in a heavier car. It had stock"j" heads match ported, with a 1.88/1.60" valve combo. A dual plane intake, a 625cfm carter a 230deg cam at .050".It had a 2,500 high stall with 4.1:1gears it ran a 12.1 ET. Gee without 2.020" inlets! and no mega duration or overlap in the cam..................Co-incidentally Their was a 426hemi in eactly the same bodied car with 4.3:1 and a 4 speed supposedly mildy  worked hemi and it ran 11.9sec ET's......................Sooo out of these 3 combo's which would you choose? all are daily drivers.Consider fuel consumption,total vehicle wieght,handling,cost of drivetrain components to live with in a daily "bulletproof"proposition. The crate 360 makes power from 3,000 to 6,800(power in  acceleration terms).The second 360 from 2,200 to 7,500peak and I guess the 426HEMI (although it had wider rear tyres)around the 6,500mark ,altough I'm not fully covinced of that.................Remember the first motor and the 426 make more power and torque numbers than the home build.GO FIGURE!...........For the Street I'd choose the home build 360.why?because it has a more effective rpm range.Having about 30 less HP then the crate 360 and 100 or more; less than the 426......It would consume less fuel and have better low speed response.It produces enough torque to keep accelerating at high rpm,meaning more speed at the wheels through each gear,then the lower rpm peaking engines which make more power???................If it was a drag car I'd definitely go the hemi........This dispells the theory that you cant make a 305 run like a scalded cat!  

And a big hello to all my chev,pontiac,old's buddies.How R'Ya'll doin'?  

But none of those are 305's.... That's comparing apples to oranges and makes no point at all.  A closer comparison would be the chevy 302 since it is of the same engine family and we know what separates it from the 305, the bore (and associated valve shrouding).  Comparing much larger Mopar engines (360-426) doesn't prove a thing about the 305.  Your logic is seriously flawed, the resistance you are seeing by everyone here PROVES that.

Even comparing the Mopar engines you changed the gearing/drivetrain which voids just about all the comparison relavance too.  

I was actually comparing combinations,not the fact that they were mopars or cubes for that matter.I cannot believe that even the 305,the black sheep of the sb chev V8 family,especially if it was deemed adequate to put in one or more models of vehicle is not worthy of hotting up?......Regardless of its standard deficiencies as you righteously argue,I firmly believe that it can be made capable of alot more in performance term........Yes,you would need to know what to do and where to do it, I simply choose and believe the 305 is worthy. Instead of just dropping in another motor..............and RESISTANCE builds strength and character.  

It was deemed adequate to reduce emissions and increase gas mileage.  Not adequate for performance.  Everyone knows this...or finds out the hard way (like I did).  Just let it go...some engines are simply not worth the effort...the 305 is the king of such engines...mainly because people like you (and me for a period of time) believe its worth building up, that everyone is wrong about it...until the first time you actually try to get power out of it and find out the hard way that everyone was right...its worthless.  But because people don't take more experienced people's word for it...this argument constantly comes up.