I have aquired a 1984 Covette 350 that has about 49k miles on it. I bought it for my daughters 88 Trans Am with a 305 TBI. The only things missing from the engine, are the intake and distributor. Can I swap everything off of the 305 to the 350? I know I cannot use the stainless factory headers from the 350, but are they worth anything, as I would like to try and get some money back from the purchase of the motor. I have read that the center bolt holes in the 88 305 are at a different angle, and needs to be redrilled. Is this something that I can do myself? Or does this need to be done at a machine shop? I also know that I have to swap out the oil pan, as it is different on the vette 350. I had a pan gasket for the 88 305, but will it fit the 84 350 as the 305 is a one piece sill? Sorry for all the questions, but I am going to try and start on the swap tomorrow, and need some answers. Thanks for your time.

 

The engine will fit, but there are some differences that need to be addresses.

You can't drill the heads for center-bolt valve covers. The difference that matters is the center two intake manifold mount bolts on each side are at 72 degrees on your 305, and 90 degrees like all of the rest of the bolts on the '84 engine. You can elongate those bolt holes on the TBI manifold so the bolts will fit the head. Oh, and just leave the Vette valve covers on the engine.

The flexplate will also be different. The 305 has a one-piece rear main seal, which dictates a change to the flexplate mounting flange. I don't know off the top of my head whether the Vette flexplate (I'm assuming you have an automatic transmission - change "flexplate" to "flywheel" if it's a 5-speed) is 153 or 168 tooth, but you'll need a 153 tooth to put it back in the car. Look for an '83-'85 application piece if you need to buy new.

I don't believe the pan gasket from the '88 will work on the '84 engine, again because of the change in rear main seal design, but I wouldn't swear to that one. The Vette pan will fit in the Trans Am chassis, so it shouldn't be a problem using the one on the 350 now.

I don't have a clue about the Vette exhaust, eBay I would guess is the best bet there.

The biggest thing is the TBI isn't going to be too happy with the displacement increase. The reasons and fixes are all discussed on the TBI forum stickies.

 

The vette pan won't fit a fbody. It extends about 2-3" farther forward.. Well it might fit if you didn't need exhaust.

The vette pan is the nuts though, has a better baffle, true bolt-in windage tray (requires studs with standoffs).

-- Joe