I currently have an LG4 with a 5 speed (yes, I understand about the tranny) and am looking to swap in a 350. No emissions laws here in Kansas. Aside from chucking the computer and flexplate, what kinds of problems am I looking at? Any advice that might save time and trouble? Recommendations in general? Headers for example.

JamesC

 

tt

 

You'll have to get an '86-up flywheel because the 350 HO is a one-piece rear main seal crank.

I'd also chuck the carb, since it is a vacuum secondary unit. Get a 650 DP. You'll need the proper accelerator cable stud either way.

Of course, there's always the option of getting the standard 350 HO, a Vortec Performer intake, and retain the CC set-up. If you don't go with a DP carb, there really isn't any reason for going with the Deluxe, performance-wise. The q-jet will bolt to the manifold that comes with the Deluxe, so you could consider the other "new" stuff that comes with it as justification for the extra expense after selling the excess on eBay.

Another consideration: Your cool dual-snorkel won't fit on a Holley.

Otherwise, it's pretty much a "standard" swap - just remember there's no such thing as a "bolt in". Little things always come up, but you should be able to handle them.

 

Hey, five7,

What a DP carb? How about an alum flywheel (this car will never see the track)? How about the stock fuel pump? I've read that the 305 chip is sufficient if I go cc-carb. Knock sensor?

JamesC

 

The stock fuel pump is fine, I'm still using it and I don't have any problems.

IIRC, Scottland is/was using his stocker too.

I kinda wish I woulda kept the CC setup, I don't doubt it would have worked...but oh well its cool.

 

I wouldn't use an aluminum flywheel for street use. GM has a light weight steel one, it weighs 16 lbs. A DP (Double Pumper) carb has mechanical secondaries instead of vacuum. It 's recommended for manual transmissions.

 

Stock fuel pump couldnt keep up with my 350HO, had to swap to a Holley unit.

 

"Double Pumper", aka "mechanical secondaries".

It probably will be. Conventional wisdom says get a 350 knock sensor.

 

I see in Scoggin-Dickey's cat, p. 94, Demon Crate Engine Carbs calibrated for the GM ZZ4 and 350/330. Both are available with mechanical and vac secondaries. Would my dual snorkel set-up fit one of these? I ask because I've heard the Demon and Holley are bedfellows.

JamesC

 

The factory dual snorkel air cleaner housing won't clear the Holley or Demon fuel bowls.

To quote: "Another consideration: Your cool dual-snorkel won't fit on a Holley."