DeHoyos

My brother's friend has an 87 Z or IROC. He has a 406 out of another car, which I believe is complete, Carb to oil pan. The Camaro is TPI w/ 5-speed. Is it possible to put the 406 in and retain the TPI setup ? If so, how much of a hassle is it gonna be ? Or would it be easier to convert to carb ??? I'll probably be the "lucky candidate" to do the work. I'd prefer to keep the TPI setup, but will the intake work on the heads on the 406 ?
I think someone told me that the angle of the carb intake and the TPI intake is diferent. Is that correct, or is it only the center intake bolt holes ? Once I have all the informatoin, I'm sure I can do it, but I wanna know what I'm getting into before I start. Any educated responses would be greatly appreciated. Thanx.

ljnowell

It could work. The problem is the TPI is horribly restrictive on a 350, let alone a 400. I think that in the interest of performance you should go with a carb. But if its just a matter of it has to run, yeah you could use it.

Riley's35089rs+

It would work , but for performance ,get some aftermarket heads and go carbed!!!

406-IROC

Go with the stock TPI system for now, but you'll need to swap the IROC's stock heads onto the 406... this way you can adapt the centerbolt style intake. Don't bother grinding it to fit the 406's heads, its a waste of time. Swapping heads is a great excuse for porting the heads, as well as re-seating, and re-sealing the valves. A fresh set of head gaskets wouldn't hurt either....

It'll run fine with the stock chip, and the stock intank pump (considering its in good condition) will also work just fine. Just raise the fuel pressure a tad, and make sure you're using, at a minimum, 22lb injectors.

I agree with the above posts that it will definitely be limited (at first), but aftermarket is always to the rescue. Larger runners, throttle body, injectors, prom etc...

Remember, have fun with it!

DeHoyos

So, the TPI intake will not bolt up to the 406 heads ? I believe the motor in the camaro now is only a 305. How is a built 406 going to run with 305 heads on it ?

ljnowell

Unless you do some work in the chambers of the 305 heads, and get some dished pistons, you may have too much compression.

RB83L69

TPI will bolt to the heads. It'll bolt up fine and work fine, as far as working goes. That's not the problem.

The problem is, TPI chokes a stock 305; what then do you think will happen to a "built" 400?

400 heads are crap. Get rid of them if they are stock. Casting numbers would be 624 or 882.

305 heads can be made to work OK on a 400, IF AND ONLY IF the pistons are the deep-dish variety. Larger valves and some porting will make them flow more or less the same as 350 heads. They'll just have smaller chambers, so the compression will be higher. But, it's real easy to get the compression way too high.

Start looking at the TPIS MiniRam. That's what you really need for a strong 400 in a EFI car.

level

i'm with the guy above go with a miniram