I have search the board, but I havent found a definate answer. This is my plan:

1. Get my 90 IROC
2. Run it for a while with the stock 350 TPI
3. Get my 400 ready to be put in
4. Put the 406 in under the STOCK intake
5. Eventually get a Mini Ram

My questions are: First, will the stock TPI intake fit on the 400? Is putting the 400 under the stock intake going to harm anything? I have heard that it wont make much power above a ceratin RPM, but I'm not sure what that number is. The car does have a ram air setup on it, if that will help anything. Someone please clear up my confusion. Thanks!

 

As long as the heads you put on the 400 have the late-style intake bolt pattern it will bolt right up. Other than that, you will need larger injectors and/or a custom chip to run it correctly. With stock chip and injectors it will START and RUN but it won't be in any way optimized, expecially if the 400 has a hotter cam in it.

Bigger injectors you can get right away- they will help compensate for the larger displacement. Custom chip I'd wait on unitl you get the miniram isntalled. No point in laying out the bucks for a custom chip that will be replaced anyway as soon as you put the Miniram on top.

I am building a 400 with Miniram for my brother's 87 GTA right now. It's gonna be a mild setup as far as cam and compression go. Even so, TPIS recommends at least 28lb. injectors for the setup. Stock 350 TPI injectors are 22lb- Just to give you a rough idea how much bigger you will have to go.

 

I'm new to the TPI scene. I have read on the PROM board about burning your own chips. It looks WAYYYY cheaper than buying a pre-burned one. I'm pretty good with electronics, so I may be able to make my own burner if I can find plans for one. Can you give me some cam ideas? I was originally going to carb the 406, and I had EVERYTHING layed out, ut now that I am going TPI, EVERYTHING has changed. What would be a wild cam to put in it? This is going to be a daily driver, but I want something very aggressive. Thanks!

 

The stock intake will work on the 400. Standard Chevy style heads will bolt right on to the block. The only modification you will have to do is have the steam holes drilled into the heads. You won’t hurt a thing by going with the stock intake or computer. It just won’t be running at its optimum performance potential. Depending on the size of the cam you choose you might have some drivability issues (surging idle, etc.) because of the stock programming, but you should be fine. The stock set-up will allow you to drive and break the motor in for you until you are able to get a more suitable set up. Even with the stock setup, seat-of-pants feel should definitely feel more powerful. Hope this helps.

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N/A 406, TPIS Miniram, 58mm TB, 30lbs injectors, Custom Ground Elgin Cam, Ported TFS heads, SLP 1-3/4", & DFI computer.
11.70@117mph

 

You rang

You will be able to use a stock TPI set-up, no problem....however, you will lose a bunch of power at anything above 3500rpm. Trust me, been there, done that I ran a 48mm TB, ported plenum, SLP runners and a superam base last year with a set of Edelbrock 6085 heads, 1 3/4 SLP headers and an Accel DFI and the car absolutely fell flat on it's face at anything above 3500rpm