400 vortec build. advice needed.

[k_pro1992]

Me and my buddies are gonna build a new motor for my truck. Want to go 400 block with vortec heads and keep stock injection and pcm. Is it possible? What all would have to be done?

 

[k_pro1992]

Planning mild cam, 2500 stall, built 4l60e, 4.56 gears. Need opinions on parts. Budget is around 1500(for motor) is it possible? Hopefully 350/450 hp/tq.

 

[Horns]

Have you ever delt with the 400 engines at all? They're kind of a different animal then the other small blocks.

Keep in mind that the 400 blocks have steam vents in them. The 350 heads will have to be machine or drilled for the vents.

 

[stroker52]

a 400 bored over 30 is a 406 with the vortec head you have to watch your compression.. the vortec heads are 64cc you can run a tighter LSA on your cam to bleed some of the low rpm compression off.. the cam will be a little choppy and the low end TQ will be moved up in the rpm band alittle.. so with that being said dont just throw a stock set of vortec heads on the motor or you will have some problems.. you need to have some work done to them to make sure they dont give you problems down the road.. have the valve guides cut down so you can run more lift, if not the retainer will hit with anything over 460 lift.. now the springs, you need a good set i love pack springs there the best out and last.. i would just have a 550 lift spring installed and you will be good.. your going to need screw in studs!! the 400ci engine needs a good cam to work right with those heads.. the intake is whats going to hold you back they flow like a chit.. like horns said above the heads have to be drilled for steam hole..

here is what i would do if i was building a 400 with a stock intake.. i would go with a speed pro 4 valve releaved piston get a set of heads from scogg & dickys ready to bolt on.. the cam just call comp cams and get them to spec out a cam for you put some roller rockers on the motor.. take the heads and lower intake to someone and have the ports cleaned up this will help alot.. run a felpro stock 400 head gasket.. the ring i would use a gapless total seal rings..

i know you said around $1500 it can be done but having all the block work is going to eat up alot of your money the heads are around $550, cam is another $300 cuz its a roller cam, pistons are $150 so it adds up fast lol also remember the 400 is a ext. balanced more so a 350 flywheel will not work or the balancer..