I have an Lg4(84 trans am) and wanna know what would be my best bet. I would like to go muti port, but wanna know if i should stay carb or go in jected. Then i would like to know what motor is not cheep, but give me the most for my money. I plan on using the car for road racing. I doing it to shut my cousins honda butt up. any info would be nice.

 

should be racing at a track not on the streets lol.
and i say just swap out the 305 and get a 350. probably get one fairly cheap. and parts are cheaper for em as well. and you get alot more power of it as well.
pay $1000 worth of stuff for the
305 or pay the same amount for parts on a 350 which would kill the 305 easy.

 

First, you need displacement to be the king. All small block chevy engines weigh the same, so start with the biggest one you can get. Don't limit yourself with a 350. If you get a smokin' deal on a 383 or 400, do that.

Next, I think fuel injection is easier to tune for road racing than a carb, but there are lots of guys going carb and doing fine. As a matter of fact, your LG4 computer quadrajet is a great road race carb, and you can tune it to run with a 383 or 400 underneath it. So...........

My suggestion is this:

1.) Buy yourselft the largest small block chevy that you can get. I suggest 400, but I'm partial.
2.) Start researching the DIY PROM and Carb forums here and learn about tuning.
3.) Buy all of the tuner equipment that you need to burn your own chips. You will have that car ripping imported cars to shreds in no time!

 

Im not talking about street racing. Will any small block bolt to the stock mount locations? I dont wanna go an all out build, cause i wanna keep it some what street able. I wanna be able to drive the car down the street and not fight it. The 455 hows the support for it? I can get one right now for good price.

 

Most semi modern small blocks will bolt completely, accessories and all. 400's were no longer made after 1978. They are a good torque motor, but the long stroke makes revving a bit hard on them. 383 strokers are well supported in the aftermarket. All they are is a 400 crank in a 350 block with a few mods. The short rods of a 400 is probably the weakest link in the bottom end, but the 383 kits use the longer rods of the 350. Actually, budget wise, you can build a 383 for less than a 400.

 

Any small block chevy will just drop in. No problems there...

As far as 455 support, I'm not sure what you're asking. 455 engines were made by Buick/Olds/Pontiac in three different versions. Support is fine, if you have the money. Putting one in our third gens is very involved and requires a lot of customizing. You should pass on that if you want just an easy streetable car. Keep looking for a 400 small block or someone's used 383 stroker. There are lots of machine shops that have them lying around to sell.

 

Ok sounds like i will let that pontiac 455 pass. I am going to look through the junkyard were all are good car go. See if i can kick up a 400 or 383. I just wanna know what else i gotta do to put them in my car. As i said before not really formilair with these cars.

 

To replace a 305 with a 350 takes 3 steps:
1) Remove the 305.
2) Swap the 305 "stuff" over to the 350.
3) Install the 350.

To get the 350 running better than the 305 did, you'll have to avoid using any 350 heads from a truck before the 1996 model year (this does not mean that any head not from a truck is okay), and replace the exhaust (all of it) & air cleaner.

 

So would the install for the 383 and 400 be the same? I have a full header back exhaust on the car(3"). I will invest in headers later. when i find my motor. Is there any tuning that needs to be done for a 383 or 400?

 

Depends. The typical 383 or 400 is "externally balanced", requiring a weighted harmonic damper and flexplate/flywheel. Some 383 cranks are coming internally balanced these days, so you have to know what you're getting. There are also "2-piece" and "1-piece" rear main seal blocks & cranks, which take a different flexplate/flywheel. Your '84 is 2-piece, but that doesn't mean you can't use a 1-piece engine.

Tuning will be mostly a matter of secondary rods & hangers, although you might need different primary jets with an engine bigger than 350.

 

Ok this is going to sound dumb, because im not used to playing with carb v8's. What are secondary rods & hangers? I am used to playing with little four bangers. Well i would like to use the stock auto trans, will it bolt to a 383 or 400?

 

The secondaries of a stock quadrajet (q-jet) carburetor are controlled in two fashions -the throttle blades, opened mechanically by the thottle, and the "air valve", or AV, which are opened by air flow. The mixture for the seconaries is controlled by tapered rods sticking in the non-adjustable secondary jets - as the AV opens more, the rods are pulled out of the jets by the "hanger". There are rods with different tapers available, and hangers that hold the rods lower or higher in the jets (higher being richer).

A q-jet will support a mild 400. The primaries are computer feedback controlled, and while the computer will self-adjust the mixture, with stock jets it may not have sufficient fuel flow capacity. I'm fine with my 350, but I'm also at 5800' elevation.

More details about q-jets are contained in the Carburetor forum.

 

Thanks that helped me alot. So this is pretty much a cut and bake swap. Just gotta find a motor. About how much should i pay for a JUNKYARD 383 0R 400?

 

highly doubt you will find a 383 at a junkyard but, it's possible.....

as for the 400sbc probably expect to pay 200-300$.

a 383 is a 350 engine with a 400sbc crank installed + minor clearencing and usually a small base circle cam.

basically you will have to find a hot rod at your yard that someone has torn down at 1 point without it being obvious or i'm sure the junkyard guys will have taken it for themselves, least thats how it works around here.

383s are cheaper to build though so i'd go that direction myself.

also yes the factory gm tranny will bolt to it and yes it may last for a little while but, not long.

the factory 700r4 auto is a tough tranny if built correctly but, it will need rebuilt and beefed up so expect to pay for that too. pm user name probuilt if your interested in this as he is the guy to talk to about built 700r4s, and he can direct you to his website and a game plan for what you need depending on your application.

also you probably have terrible gearing in the factory rearend which you also may want to adress further down the road.

 

Yea i know the rear end needs gears, but it has already been taken care of and installed lsd too. I now have 3.73s and matching speedo gears. I wuld like to keep it auto, but put in a v gate shifter or something like it.