TBI Adapter Plate Finally Finished

[Chris in Idaho]

Thanks for all the feedback. I'm visiting in SoCal this week and I plan to head by Specter so maybe I can pick up a carb insulator while I'm there to help me mock stuff up.
It's sounding like an open plenum adapter will work best. I'm used to v8 intakes that have two separate planes and if you want to keep your bottom end torque you need to keep them separated, but on the LC engines the air all ends up in the same space once it gets past the insulator anyway.
If I make an open one, I'll have to include a new open insulator also, or do like Downey suggested and just make a taller 1 piece adapter. My only hesitation is I don't want to have to raise my price but this would definitely add expense.

 

[Chris in Idaho]

Great job!

Now, how about a plate for the 20R/22R 4 cylinders? Not everyone wants to perform a 22RE swap, and I'd really like to build a 20/22R hybrid and use GM TBI injection.

Would you want to use the 1BBL throttle body from a 2.5L 4cyl?

 

[FJ40Jim]

Whould using the old 69?? manifold with the longer runners help in getting more air to the motor?

It might flow better,but the real issue is mixture distribution. The later manifold has skinnier runners to the end ports to keep velocity up and reduce the opportunity for the fuel to drop out.

 

[Chris in Idaho]

Ok, here is the offset version mounted on a 1F. There's room next to the connector now so there's no pressure on the wires. The harness will need to be connected before the throttle body is installed because there's still not quite enough room to get the connector on and off next to the valve cover.

 

[YotaJosh]

Would you want to use the 1BBL throttle body from a 2.5L 4cyl?

I though about that route, but I'd rather have the 2bbl from a 2.8 or 4.3. Probably a bit overkill, but I'm sure you could detune it a bit.

 

[Chris in Idaho]

No prob, do all the 20r and 22r's use the same carb?

 

[FJ40Jim]

Yes, basically, all 4-cylmintruck use the same carb.
They use the same bolt patter as LC 2-bbl, but the carb itself is a much smaller unit.

EDIT: the above is way too general. There are some years in the 1980's that are the same mounting as LC, but there are earlier carbs that are very different. Sorry, don't know exactly which years....

 

[Chris in Idaho]

Is there anything that might cause a clearance issue? Could I just send you one of these LC adapter plates (probably the centered one) and it should work?

 

[YotaJosh]

No prob, do all the 20r and 22r's use the same carb?

Actually, the pattern differs a bit. Most Weber adapters accommodate either 20R or 22R.

Is there anything that might cause a clearance issue? Could I just send you one of these LC adapter plates (probably the centered one) and it should work?

It might. I'll have to take a closer look at my manifold and see.

 

[Chris in Idaho]

Are you using a GM computer, or aftermarket?

Sorry I didn't have an answer sooner, but yes they're using a GM computer.

 

[CruisinGA]

Sorry I didn't have an answer sooner, but yes they're using a GM computer.

Great, thanks.