I've got an unmolested 327 and would like to build it up a little and put in my 1978 GMC truck.  I don't want to go balls to the wall insane, just want a real reliable daily driver that I can take to car shows.  Any recommendations as to how I can build it up.  I want to do all the assembly myself but farm out all the machine work.  Is it worth keeping the original heads and rebuilding them?  No there not 2.02 heads or double hump heads.  And it's a two bolt main block.  Should I go 30 over?  Is it realistic to get 300 HP out of it?  Help me if you would please.  Thank you.  

What's your budget?

Does it run?

If so, I'd do a simple top end upgrade.  Running head on into the bottom end rebuild can slow you down a lot, and is unnecessary if it already spins and doesn't leak oil.

I'd get some assembled World Product Sportsman II cylinder heads.  Dart's new heads are supposed to be really good budget heads as well.  Get a good valvetrain kit.  Something like 280/280 would be a well balanced ride.

Edelbrock RPM Air Gap manifolds are awesome intake manifolds for the street.

Then, grab a 1" spacer and a carb.  You can find some 650/750 Barry Grant carbs on eBay for pretty cheap.  I found one for like 55% of its original value because it needed a thread repair job on one side.  

Well, it's too late, the damage is done.
I've already torn into the whole engine and disassembled it.
I got overzealous.  A learning experience.  Good or bad? Don't know yet.  I've got to find some info out there on what to do next.  The local machine shop here said to have the crank turned 10 under with new bearings.  Keep the rods and get 30 over pistons and rings.  As far as the heads go I'm thinking of having them rebuilt and using them again.  This engine is going to be my teaching tool for me.  As far as budget goes, I do a little at a time when I can.  The engine dosen't have to be up and running right away, so I can take my time and learn and make mistake.  Hopefully not too severe mistakes.  

No, no.  That's perfect.

I was going to recommend keeping the stock internals and upgrading the rod bolts to ARP.  That's like initial the christening hot rodder moment -- ARP rod bolts.  They totally have a monopoly there.

If you want an element of control, as well as trustworthy (and warranteed) machine work, you can buy and supply the parts you specifically want to go in the engine.  Let the machinist know what the engine is gunna be used for, give him those few performance parts for the bottom end (like rods--see next next paragraph), and (s)he'l do the rest.

I'd ask him to supply you with a good-to-go short block in a few weeks.  It's not as manly as building a short block from scratch and using your teeth for a torque wrench, but it'll get built a lot faster and you won't have Chronic Tight Anus Syndrome (CTAS) while you're riding on the highway.

Do a Google/MorTec check on your rod numbers (or ask your machinist) to see if they're cast iron.  That's the one item you want to be forged, in my humble uneducated opinion.  SCAT and Eagle make awesome street rods for around $200 or so a set.

From there, you'll need an oil pan to match your oil pump pickup.  Then you can go back to my first post.

Good luck--you'll do fine.  The first time I did this, it was with a '79 Alfa Romeo inline 4 that had to have parts and tools special ordered from Italy to run.  

I did a badass job, though, because it was running on just three cylinders for months before I decided to get it professionally rerebuilt.