305 TPI

[nate3531]

is there a difference between the TPI manifold on a 305 and a 350? I found a full TPI engine and transmission from a Camaro for $150. I am somewhat interested in a TPI conversion cause it is a very cool looking setup. Is there any real advantage over a stock TBI?

 

[68post]

There isn't a manifold differance - just larger injectors for a 350. There is a great differance between a tbi on a stock manifold and the flow of a tpi (which can also be improved from it's stock configuration).
You should gain alot of torque and also some HP.

 

[zraffz]

As stated the 305 and 350 TPI is the same, only difference is injectors and I believe the computer.
I'd imagine swirl port heads (tbi heads), and a TPI manifold would actually work out well on a truck. The problem with the tuned port manifolds that come from GM is that they flow very poorly. You will be gutless from around 4,500 RPM and up. If you are that interested in it I'd go with a Weiand Stealth Ram intake... looks like a 350 ram air setup and is an extremely well flowing dual plane setup.

 

[68post]

As stated the 305 and 350 TPI is the same, only difference is injectors and I believe the computer.
I'd imagine swirl port heads (tbi heads), and a TPI manifold would actually work out well on a truck. The problem with the tuned port manifolds that come from GM is that they flow very poorly. You will be gutless from around 4,500 RPM and up. If you are that interested in it I'd go with a Weiand Stealth Ram intake... looks like a 350 ram air setup and is an extremely well flowing dual plane setup.

The Stealth Ram is actually a well flowing tunnel-ram style setup, but nothing to do with being designed like a dualplane intake. It is just like the GM Ramjet intakes.

Have those TPI heads ported and use them instead of the TBI swirlport heads if you want more topend power. It should be VERY torquey below 4,000 rpm with the swirlports. (great truck setup - in my opinion)

 

[nate3531]

Thanks for the replies. Torque is my goal not top end rpms so I would keep my swirl ports. Just need to buy larger injectors and get the computer. Next question will that computer plug in directly or do I need to swap the harness from the donor car?

 

[Chris]

Thanks for the replies. Torque is my goal not top end rpms so I would keep my swirl ports. Just need to buy larger injectors and get the computer. Next question will that computer plug in directly or do I need to swap the harness from the donor car?

Well, first of all is it a MAF or SD system? You want SD, since the early MAF systems sucked ass.

If it's SD, it will run on the stock 7747 ECM if you wire each bank in parallel with each injector driver. It will need a tune to run properly though.

Another option is to use the actual TPI ECM, but it will need to be re-pinned and you'll still need a tune to disable VATS. I don't know the broadcast code off the top of my head. You can't swap the harness. You'll need to find pinout diagrams and re-pin your wiring harness to the TPI computer.