Lets build a 400

[youngblood78]

Hello everyone I recently purchased a sbc 400 with the intention of building a nice reliable torque motor and im asking for your imput and guidance. Ok to start I ive never built a motor before replaced a few head gaskets but thats about it.
I do know alittle bit about most of this stuff just reading all of your posts on here but again only way to learn is hands on..

So what ive got is a early 70s 4 bolt main. 400 cast#3951511 from what I can reseach it was a 255 hp motor from the factory.
Im looking more for 350hp 375tq or a little more. Torque off idle and still rev up there with out concern this motor will never see RPMS above 4500-5000. But I would like to have the ability to drop a gear and pass some preus doing 50 in a 55. Lol.

My plan is to find some Vortec heads to replace what it had I know ill need to drill steam holes that dosnt seem to big a deal
Would like a roller cam and lifter setup (maybe rockers to)
Flat top pistons
I would like to use the factory crank and connecting rods but maybe you all could steer me in a better path.

As far as a carb im up for imput I have a good quadrajet in the truck now but if theres better im game

Here is a link to something I found that is very close to what I want to build

http://www.hotrod.com/how-to/engine/...ster-for-2500/

This is going in my 78 k20 with a sm465/205 and 4.56 gsears with 33s the 350 in it now is pushing 2500rpm at 55 so it needs to be able to handle the rpms
Any imput will be greatly appreciated and I will post pictures of what I have asap

[bnoon]

Skip the roller cam idea. There's no need for it in a low RPM high TQ motor like you're wanting. Put the extra money into the GM Performance Parts Vortec castings and you'll be much happier than rebuild stock Vortec heads. The GMPP ones flow better and have thicker castings all around for things like needing to drill steam holes.

With the 400 cubes, I'd choose something from Summit's camshafts like the 1103 or 1104 for a nice broad curve. Some would say the 1101 or 1102, but with the extra cubes those really are too small.

What pistons are in it now? Unless it needs pistons due to wear or damage, I would just clean and re-ring them if they are usable. Early 70's, if before '74, should have decent pistons in it. Pictures of these please.

[Jrgunn5150]

Originally Posted by bnoon

Skip the roller cam idea. There's no need for it in a low RPM high TQ motor like you're wanting. Put the extra money into the GM Performance Parts Vortec castings and you'll be much happier than rebuild stock Vortec heads. The GMPP ones flow better and have thicker castings all around for things like needing to drill steam holes.

With the 400 cubes, I'd choose something from Summit's camshafts like the 1103 or 1104 for a nice broad curve. Some would say the 1101 or 1102, but with the extra cubes those really are too small.

What pistons are in it now? Unless it needs pistons due to wear or damage, I would just clean and re-ring them if they are usable. Early 70's, if before '74, should have decent pistons in it. Pictures of these please.

I've been trying to find the GMPP head's you're talking about for some time now, do you have a link? All I can find are SDPC ridiculously overpriced ones and GMPP Production head's like these,

http://www.summitracing.com/parts/na...IokaAo1p8P8HAQ

Btw, this is the follow up to the 400 build in Car Craft,

http://www.hotrod.com/how-to/engine/...l-block-chevy/

[youngblood78]

I will pist what I have asap it has the stock dished pistons bit will need to be bored out at leat .020 over so new pistons are in order

[wideopen1967]

96 - 99 vortec heads with 22cc dished pistons bore .030 will give you 9.5 -1 compression. Add a mild cam 350 - 375 horsepower with gobs of torque. I will probably do this build soon.


http://www.hotrod.com/how-to/engine/...ster-for-2500/

[youngblood78]

Wideopen.. as far as mild cam what are you thinking? Im new to this so everyone please forgive my ignorance.
I dont want this truck to have a major lope to it. Need it to idle in gear in the feilds its a work truck. And as far as rpms what is a maximum rpm for this setup

[wideopen1967]

Originally Posted by youngblood78

Wideopen.. as far as mild cam what are you thinking? Im new to this so everyone please forgive my ignorance.
I dont want this truck to have a major lope to it. Need it to idle in gear in the feilds its a work truck. And as far as rpms what is a maximum rpm for this setup

A 400 is a good torque motor. With the stroke I like to keep the RPM below 5000. With that said you want to match the cam to that torque curve. I like this cam from Lunati, pair this up with a 1500 stall and you cannot go wrong;

https://www.lunatipower.com/Product....d=2324&gid=287

[youngblood78]

That looks like a good contender if the truck were automatic but its a 4speed