Thread: 305 needs help

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Originally posted by chaos_defined
I am new to rods and am building a 91 chev caprice for my first.

I have the 305 with 207000 mi on it

I want to keep the 305 but also want to pull more power out of it

any ideas????

It is time for a rebuild.

What would you do to the ignition?

I already have the exhaust done other than headers, I have duals running 2 1/2 in di back to flow masters with a 3 inch out.

as far as a rebuild goes i thought about it but i dont have cherry picker or engine stand....

If i knew some one round here that was into cars that would do it i would in a chevy heart-beat!!!!

Low budget mods:

1. mod the exhaust using the copcar (9C1) larger Ypipe (1991-1993 applications with the 350, but fits the 305) and an aftermarket muffler. Make sure stock cats are not clogged (which would defeat any gains by modding the exhaust).

2. make a dual snout air feed on the plastic toaster box air cleaner. See the pix on the Impala SS forums under the TBI and Engine sections. You use junkyard parts to add a second air feed to the passenger side of the air cleaner. Factory looking, cheap.

3. Mod the inside of the airbox (behind the air filter) by adding several large holes to the air silencer ring/support. Keep the support though because it's a reinforcement for the air cleaner box.

4. 1.6 stamped self-aligning rocker arms ($75 at Scoggin Dickey) is a cheap way to add lift/flow, to make up for the very small stock cam.

5. Tune up, new fluids. CLEAN the TB and injectors. Replace the CTS, and do a rebuild on the TBI. Check the distrib, make sure no oil in there (which degrades the magnetic sensor and gives poor ignition).

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EDIT: oops -- you already have duals. The other stuff still applies then, and you might want to raise the fuel pressure slightly to provide a little extra fuel now that you opened up the exhaust. See the Tech Articles pages that begin at http://www.thirdgen.org for the one on adding a shim (a quarter, $0.25) into the TBI FPR (fuel pressure regulator).

Yes, 200k miles is a lot, but some taxis go a lot further than that. It makes no sense to spend any real money on modding the engine, but if the engine still runs well then it makes sense to do nothing to it but cheap bolt ons.... and then keep driving it. If the body is in good shape you can always get a junkyard engine and rebuild it while you're still driving the one you have. HTH.

Why not buy an engine stand, use the money you have now to start building a good engine for it. Just buy the 383 and hang it on the stand. As time and money permits start obtaining the parts you need to finish the 383. When it's all ready, rent a cherry picker and switch engines. A 305 with over 200k miles isn't worth investing a dime of money or time in..... JMO

yeppers I have to agree with others on here. 200k+ on an engine is well past the rebuild time for it. You will have to rebuild it before it gets too bad.

the 305 will likely cost you more than the 383 will. The 305 would be fine if it weren't for all of the emissions crap they had to strap on to it. You might try looking into a 92-96 cop car(9c1)that was wrecked. It has a 350 (LT1) engine and a replacement computer you might want(oh yeah you might want to save the wiring harness from it too... learned that one the hard way). I picked an engine up for $500. Then get yourself an engine hoist.

Nasty ol 305 ,I like my 305,just quit pickin onn the 305 ,when I blow it up from lack o power ,Ill just bolt the interchangeable parts on the next block ,which will be a 350!!Some people just have learn on their own.Build the 305 and then u will know,and there is no wasted time or money ,because u gained the exsperiance from ur money spent

buy the 383 for $450. great price. TBI will work, but u need bigger injectors. use holleys stealth ram intake for more torque and horsepower. U will have to wire the computer still if u havent done that. If u go with a carb, use a edelbrock intake with a holley Street Avenger or Edelbrock Thunder Series carb. I used the thunder series on my 305 in a caprice('88) and it ran real good. If your running a 700R4 transmission youll need to get a lock-up kit for it. Youll also need the kickdown bracket either way you go(Carb or fuel injection). If you dont buy this you will burn your transmission up, I burned mine up. Since your workin with $900 I would use a carburetor because injectors arent cheap. You will need...
around $500 for avenger or Thunder series carb
around $150 for distributor(and kit)
around $100 for lock-up kit(Transmission)