1987 5.7 tbi off g20

[evilunclegrimace]

I have a question, was the intake manifold cast iron or aluminum?

 

[L31MaxExpress]

I have a question, was the intake manifold cast iron or aluminum?

The only SBC TBI manifold that I have seen that was cast iron had 2" bores, a cast shut EGR and was on a school bus. Probably used on boats as well.

 

[evilunclegrimace]

The only SBC TBI manifold that I have seen that was cast iron had 2" bores, a cast shut EGR and was on a school bus. Probably used on boats as well.

I have a cast iron intake off from a '92 G3500 chevy van that I bought from the original owner. I will go out and measure the TB bores a take a pic.

 

[evilunclegrimace]

The bores are 1.760. The part number cast in the the intake is 10093015.

 

[wumiguel26]

Was it that clean inside or did you have to rebuild it?

Had to have it Machined then went .30 over and a stage one jamsi camshaft

 

[L31MaxExpress]

Had to have it Machined then went .30 over and a stage one jamsi camshaft

Sounds like a nice build. Is it the little 184/194, .368/.398, 104 LSA MPG cam? That little cam should love cruising in the lower rpm and deliver great mileage. Love watching the Jamsi stuff on their Youtube channel.

 

[L31MaxExpress]

The bores are 1.760. The part number cast in the the intake is 10093015.

That is weird. The 92 G20 I pulled the TBI system off for my 83 G20 back in 2004ish had a tall aluminum manifold. The runners look lower and shorter in that one.

 

[evilunclegrimace]

That is weird. The 92 G20 I pulled the TBI system off for my 83 G20 back in 2004ish had a tall aluminum manifold. The runners look lower and shorter in that one.

They are short. The manifold is a cast iron copy of the standard aluminum manifold that came on pickup trucks, It just weighs about 3 times as much