Any Chevy experts out there?

[Mickey_D]

Well, the forum section IS "Off Topic".....

Anyways, I've tried asking on a couple Chevy forums to no avail. None of them even bothered to reply, so I'm hoping some of you might be able to help me out.

I'm getting a 1990 Silverado (blown engine) and currently have a rusted out 1981 Custom Deluxe. My old truck of course has a carb 305, the Silverado has throttle body 350. I'm going to transplant my 305 into the Silverado, but can't remember if the 350 throttlebody ECU will be sent into hysterics by the 305. Can I just bolt the 350's intake onto the 305 and run with it?

I'd rather have the TBI's reliability and fuel mileage over the carb if I can do it.

Any help in locating a source for the info or if you have personal experience would be greatly appreciated.

[Mac]

can't say for sure, but I bet it would be fine, the engines really haven't changed much over the years, you might have to swap the heads or something, but the block itself has remained virtually unchanged.

it might run a little rich with the TBI designed for an engine thats 45 Cin larger, but thats like 700CC's which isn't a huge differance on a large engine like that.

me persoanally, I would just do it and deal with any problems as they popped up as I don't expect you would have many.

[Typrus]

Biggest thing I think you should look for is whether the intake manifolds are cross-compatible in stock form. If I remember, I'll do a quick look-around for you.

So what about the engine is blown? Just a spun bearing, bad rings? Gasket?
A 350 should not be hard to work on, especially if it is just a TBI.

The best thing I remember about our 305 1500 Suburban was when my dad would flip the air cleaner lid over and it would get that carb-style "whoosh" sound... Real muscley a 6 or so year old me thought. The 350 2500 Suburban we got later was a Multi-Port, so no air cleaner flipping...

My mind on Chevy? Every one we've ever had was a junk-heap. Fords? Our 2002 Excursion has near 100k... Not a single problem yet. On stock brakes amongst other things. We went through a set of front discs on the Suburbans every other oil change or so. Yuck. Trannies would blow around 60k... Man... Bad memories of maintainence. But man oh man.... Those small blocks.... They sounded so..... Ohhhh man... Ehem... Sorry.

[ARCHINSTL]

like 700CC's which isn't a huge differance on a large engine like that.

I know that there are much bigger engines out there - but that little 700 cc difference is like half of our mills....
Tom M.

[Mickey_D]

Heh, as with any car, you get some lemons, you get some diamonds. I appear to have gotten a diamond. 335,000 miles and the only thing not original on it is the carb. Oh, and the starter.

Typrus, as far as the 350 goes, it's fubar. There's a piston missing if that gives you any idea. I believe he was towing a horse trailer with it and tried engine braking it. He has since sold off the heads, too. Hence why I want to just transplant my block and heads over and use his intake and exhaust manifolds. If I can that is....

[Typrus]

The heads apparently won't crossmate on some 305's and 350's.

Engine braking with a load isn't bad. Downshifting to 2nd at 80mph to engine brake is bad. lol. I'd imagine something like that happened.

Again, see if the intakes or even if just the TBI mount line(s) up.
Something else to look for is if there are any extra sensors in the TBI one. Knock, etc. I don't think there are any extras, but it is a good thing to look for. A place I read said that the PROM chip MIGHT require a reburn if you chnage the displacement of the engine under the TBI by more than 10%, and that going more than 30% is no recommended. So you might require a PROM burn to lean it out a bit. Unless you port and polish the heads and get the flow up to similar of that to the 350. Its not impossible.

[Typrus]

I looked at a few 350's today. Most were either carb or Multi-port, but the one TBI I found had the EXACT same intake manifold as the 1 305 we have at college. 6 bolts on each side, enter the mani at an angle. Most of the MPI's were 4 bolt straights.