RyanWilson

I have a 1989 IROC 305TPI, i have sitting in the carport a 1982 5.0 carb'd engine. would it work if i just swapped the heads and intake over?
OR
i beleive i can get a 350TBI engine from a chevy truck. should just be able to transfer the intake over? for this engine was planning on changing the cam. what would be the expected result of running a cammed 350 on a 305ECM?

Guest

Use the 350, fine. You may need to change injectors. But not those 193 heads.
Is your '89 a factory T5 with dual cats? If so, use those heads and that cam for the 350.
Otherwise, use the '82 heads, and then either mod or swap your lower intake manifold to match.

RyanWilson

Once was a single cat car currently has no cat & has headers.
82 heads on the 350? what intake would be available to retain the tpi system? or what mods would be required? opening up the intake manifold ports to the heads or porting the heads?

cost i would prefer to keep on the lower scale, this car was once mine. i blew the motor (rod through the side of the block) on our vacation three years ago. just left it in parents garage ever since, just recently pulled it out because my girl friend wants to drive it - since i decided to sell her supercharged 40th GTP this past spring.

Guest

For '87, Chevy changed the angle of some of the bolts holding the intake manifold to the heads. The center 2 on each side. This does not apply to the 'vette aluminum heads. The correct solution is an '85-'86 Camro, or '85-'91 'vette lower intake manifold, but the later version you have can be drilled.
There is no porting required.
Since yours wasn't a dual-cat version, you shouldn't have the good '081 heads, and the '82 should have the '416 heads. The TBI 350 should have the '193 heads. The '416 heads will perform better than the '193 heads.
Porting would help, as would larger 1.94" intake valves. But porting is not necessary, and even without porting, and with stock 1.84" intake valves, the #416 heads will perform better than the #193 heads, which do have 1.94" valves, because the #193s are swirl-port.

RyanWilson

im a little nervous about drilling a hole into the intake. my mechanical skills are good but whats the possibility of error in this case lol. i am assuming this hole would have to be drilled at exactly the right angle if not i would have to oblong the hole making a possible leak? what about the old holes?-gaskets covers them up nicely, fill them with silicone as well? this portion of modification is new to me.

Guest

There's virtually no chance of you creating any leaks.
The main issue isn't you elongating the center 4 holes, it's that afterwards, when you try to tighten the bolts, they're no longer square to the intake. What's really needed is some shims, of about 18 degrees, or cut flats into the manifold.
I helped a friend try this, we ended up just using grade 8 bolts and letting them chew into the manifold. He drove it that way for a couple of years.

RyanWilson

i also have a 1988 307 from an olds cutlass in the backyard, still in the car. but would those heads be any good or better than the heads from the 1982?

vetteoz

iTrader: (13)

Alternative is a large flat 1/16" thick washer,it will deform when bolt is tightened up spreading the load on intake surface

RyanWilson

well didnt end up going that route. found a recently rebuilt engine from the wrecker from a 88 firebird got lucky. 350tbi. so i just changed the intake. this engine was spotless in side so clean and shiny. apparently the car it came from was gorgeous according to my father in law who picked the engine up for us. chatty guy lol talked for while to find out they still had the car it was from. he saw the car it was all fixed up nice, but recently hit in the front end and written off. apparently the wrecker knew this guy with this car previously so they had the low down on all the repairs. so anyways just swapped the intake and now its running just have to set the timing tomorrow.
thanks for all your suggestions.