305 to 350
 

I have a 305(LG4). My question is can I take the top end (intake ,heads ,carb.)off the 305 ,and put it on a older 350 block? Will I be able to use the same ECM or will I need to change? I have a 350 motor I can obtain. I thought I would put Comp XE262H cam in it ,and maybe put headers on it. Will the wire harness still work? What about the emmisions crap? Can I do away with it? What kind of HP gain would this setup give me?Please help.:hail:

The intake, heads and carb will work just fine on a 350. The ECM might go kinda funny though so I would recommend getting an ECM from a computer controlled 350 carbed truck. And your flexplate/flywheel wont bolt up to an older crank. It will give you a huge hp increase since you are replacing the LG4's small exhaust and puny camshaft. The swap from the will give you about 10 more horsepower and 30 more foot-lbs of torque roughly.

The heads will fit and it will run, but unless you have dished pistons, clean up the bowls and ports, and put in bigger intake valves, power will be substantially limited. You'd be much better off getting aftermarket 350 heads and flat-top pistons and doing it right.

This should not even be considered without exhaust upgrades. The factory LG4 exhaust chokes a factory LG4. 'Nough said.

The ECM will be fine if the cam is kind to an ECM. The compucams are a little more expensive, but don't give the computer fits. Mine has .454"/.480" lift w/1.5 rockers, 216/228 duration @ .050, 112 degree LSA, and the computer is fine with it. Other cams with lesser specs will make the computer throw a hissy fit.

The status of the emissions equipment is purely between you and the fine state of PA.

Do it right, and you will easily double your current horsepower (I may have even done that with the 305). A 350 CC setup is a great daily driver with good manners and plenty of spunk.