I was thinking about building my first motor. and i don't want a common 350. I was thinking about a 406 or somthing diffrent. what would I have to do to make that motor run right with a tpi. Its going to be daliy driving, and I want about 350 hp and 400 tq, and ocasionly a shot of n.o.s.. Thanks for all the help!

 

An engine that big is going to need lots of air. You will need some serious porting of the plenum, runners, manifold, and even the head. I would also get a 58mm throttle body. You will probably get a lot of people tell you that you shouldn't put TPI on an engine that size but if you can get enough air in it, it should be okay.

 

I believe a month or two ago, Super Chevy did a write up of an EFI 406 for the street. They compared an Arizona Speed and Marine TPI set up (larger runners, base, TB) to a 4 barrel TB multi port set up (aftermarket). I can't remember the exact figures, but that TPI set up featured in SC leaves your 350 hp and 400 TQ desires in the dust! A TPI 400 is just a TQ animal, which is very good for a street engine. You shouldn't have much of a problem building your own 400 TPI as long as you tune it when you're done...

 

400's and TPI ROCK

Even a VERY MILD 400 with a decent set of heads, a well chosen cam, and a STOCK TPI w/ maybe headers and a cat back added will be a TORQUE MONSTER.

I'm still debating on putting together a Vortec headed 408 w/ TPI....just weighing some other options and trying to finish some other things on the car first.

I helped screw together a Vortec headed 406 that was actually really mild. The heads didn't even need work, since the cam lift was in the .460-470 range. And with headers, the mild cam, and the Performer RPM that motor was downright EVIL on rear tires.

Even in a heavy 70's car, it makes my L98 feel like it's got NO bottom end


350 HP / 400 ft/lbs? You can build a budget 400 to push an easy 360 HP / 440 ft/lbs with just some attention to detail....go for it.


Tuning / burning your own PROM for the TPI will help GREATLY too, although a mild 400 will run pretty good on a 350 PROM. Not it's BEST mind ya, but good enough to make you know your local tire guy on a first name basis


HTH

 

thanks for all the replys! these is going to be my first engine build, I don't feel like porting anything. I just want to put things together. Is a 406 to big for the stock tpi?

 

If nothing is ported, with stock heads, and stock TPI intakes, you should be fine with a 400 based engine. Probably need a bit more fuel though via larger injectors and/or AFPR.

 

thanks for the help! so whats a good cam for a 400 and tpi?