i just recently purchased a 82 el camino ss
it has the original trans and engine (305) with over 200k miles

i bought this car knowing i would need to replace the engine and trans soon

i would like to know what size engine's i could put in it.

it seems most people put a 350 in it is their any other sizes that will bolt up easily?
this car has a carb would it be very hard to change it to fuel injected?

my goal is to produce around 400 hp and torque
also i dont know what trans is in this car
anybody have any ideas.

i will want to put a stall in it
not sure if i should have it rebuilt or put a different trans in

any info would be helpful  

most 82 and up gm mid size cars are set up or have the proper holes in the dash for standard factory fuel injection harnesses....

any engine sbc, bbc or LS1 type can be installed in that el camino... the LQ9, L92 head motors seem to be hot right now..

which ever gm trans it has it will need to be replaced/rebuilt with internals that can handle the power you are describing...  

They came with a th-350 or a th250 If it is a th-250 or a th-350 the pan should be square with the rear passenger side corner of the pan flat.The th-350 will have a pan with a smooth flat bottom and the th-250 will have a X stamped into the bottom of the pan if it is a th350 I would rebuild that one but if it is a th250 I would replace it with a th350.For the engine you should not have a problem getting 400h.p. out of a 350 s.b.c  

how hard is it to swap a 305 engine to a 350? Is their any thing i need to look out for or be ware of before i start this project?  

the only drawback is if you have factory feed back carburation....  the carb jetting is too lean to compensate for the larger motor... (the carb will have wires to the right front top of the carb) they did make 350 versions of this carb so all is not lost...

and i have had a few people get the feedback q jets off 81 cads with the 368 iron motor to use on the 350 as this lets the carb supply the extra fuel a hot 350 needs...   and allow the conputer to still control the fuel mixture with the oxygen sensor for the best fuel economy....we use some of the parts out of the cad carb....  

Even though you can, putting a big block in any G-body requires a fair amount of labor. Also, you have to notch out or completely remove the A/C box on the passenger side firewall to clear the BBC valvecovers.

The best thing ot look at is either a Gen I or LS-series motor. With GM Performance Parts new plug-and-play harness for the LS-motors, putting an LS2 in your Elky would be really easy, and it would roast the tires.  

I know! go to a junkyard and get one of those new 6.0 distributorless engines that use the smart-coils, get the trans and the sensors, and order a MSD LS1/LS6 Computer box and software, bore it out, raise the stroke, switch out the cam, order new valve train parts for the heads, then decide whether you want it to be carburated or fuel-injected, order an electic waterpump, switch out for electric fans and shove it in the El-Camino, and have a blast!!!!   Sorry i get carried away sometimes, but it would be cool      

Yes, definitely if fuel injection is your thing, the GM 6.0L engines are amazing. The new Caddy 6.2?L makes 401hp stock, so if you could find a wrecked escalade somewhere you'd have a stocker making your power goals. The LS series easily can support more than 400, and even the LT1's from the early 4th gen's can crank over 400. I believe it was car craft that had an article on a 9-second LT1 camaro w/ stock PCM.

Just go by availability though, and don't impulse buy. There was a '78 Elky for sale around these parts with the 305/th250 combo for cheap that woulda made a killer sleeper. good luck to you