I have a 817 casting 400 block. I would like to get 400 H.P. out of it. I plan on a .030 bore to a 406 with domed pistons but would like advice on cam and intake selection. I am looking for low and mid range power. Engine has stock heads with 1.94" intake and 1.5" exhaust valves. Should I use these?

 

A 406 with domed pistons? You want to use stock heads ?

ok ok, lets step into reality here. You don't want domed pistons with a 3.75" stroke 400 block. Unless you plan on running race fuel. You'll want a moderate dish.
You'll want to throw your stock castings in the garbage.

It sounds like you have no idea where to start, and a generic queston on this forum is a poor way to begin. Do a search, pick up a few magazines (from this decade please, if it recommends domed pistons and camel hump heads it's an old magazine!), and maybe even a book (David Vizard, hint hint) and start reading!

 

I was leaning towards domed pistons for the compression. I've never built a 400 only 350s.I did not say i wanted to use stock heads just wanted to know if I could reach my H.P. goal without changing them. I have no issues with replacing them.

 

It shouldn't be to hard, with a healthy cam and decent heads intake and exhaust should put you at 400 HP, it just depends on where you want to make your power. and how much money you want to spend.

 

here's a neat build I found a while ago

http://purplesagetradingpost.com/sum...%20engine.html

 

No, you'll have a tough time hitting 400hp with stock heads. Unless you *carefully* pick your cam, and are a good porter...

domed pistons on a 3.75" stroke engine will give you 12:1 ++ compression. Use dished pistons. That'll put you in the 9.x range, which is what you want for the street.

 

I would like the power at the bottom end. I've never been big on high speed. I'm looking at about a $2000 budget for parts. Thanks for any actual advice for a newbie here.

 

keep your eyes out on craigslist, and local swap meets, you'll prob be able to find a decent set of heads for a good price, I got a set of world sprtsman II's for $500 with roller rockers. If you go with a roller cam, expect the bulk of your money going to valvetrain parts(about $1000), it's worth the money though. be sure to match your heads cam and intake, "the whole is worth more than the sum of the parts"

Good luck-

Eric

 

If you're wanting your torque at lower rpm, you most definitely want dished pistons. It's so easy to build compression with a 400 and 64cc heads, which is what most decent heads are offered with.