I was wondering which would be a better horsepower/torque monster.
A 383 or A 400sb.
I was thinking of getting a 383 kit but due to the different clearances I wont be able to run a regular high lift cam that cost alot.
So would going to a 400 be the best solution.
I was thinking a 4 bolt 400,bored 0.060 over, forged pistons, 10.4:1 cr, w/vortec 350 heads(Im not sure on the steam hole modifications or if you even need them)
, hydraulic cam around .525/540 lift or roller w about .580/.580 lift, rpm air gap intake , proform mainbody on my 650dp, would equal a nice setup?

 

The 400 has 17 more cubic inches than the 383, so naturally it's better. That is, if you can find a 400 block. The 400 and the 383 have the same stroke, so you'd have the same cam clearance on the two. I don't know why you'd have a problem with it though.

 

2 bolt 400s are stronger webbing wise than 4 bolt 400s believe it or not.

Why bore it .060" over? don't bore it unless you need it. boring is a maintainance procedure, not a power making procedure. I promise you won't feel the difference between a .060" and a virgin bore.

Do the steam holes. Doesnt hurt and all it can do is help.

 

Good luck finding a 400 block that will accept a .060 overbore, and still be stable. Also, the 4 bolt block is weaker than the 2 bolt. You would be better off with a 2 bolt.

 

383 stroker is the way to go in my book for one its easier to find a 350 block compared to the 400 and you can make some pretty impressive numbers with a 383

 

awesome . thanks guys.
I just thought there was a greater advantage of stroking a 350 compared to building up a 400( like rpm wise or something).


WOw I didint know the 2 bolt 400 was strong.
Believe it or not, where I live there are more 400'ds for sale than 350's.
But it seems like each week, 10 or so 350's are picked up by someone so the supply is dying down but Ill snag what I can get.
THanks

Check THIS LINK OUT...look at their setup..IT IS INSANE
471lb.ft torque under 5500 rpm..WOWOW
http://www.chevyhiperformance.com/te.../148_0306_406/

 

because the piston comes down do much further in the block with the 383 the cam comes really close to the piston skirt (i had this problem when i stroked mine) you can run a good .510 lift with no probs in a 383, maybe a little higher, i'd go with using a .510 lift or so cam with 1.6 roller rocker arms to get the lift you want

 

Couple of points to consider. When building your 400, order pistons that use a 5.7" rod...not the factory 5.5" rods. This will decrease Rod angularity which will decrease thrust loads on the major axis. Will also give you a better Rod to Stroke ratio which will enable you to run more RPM and more HP. Always good. If you can, run a 6" rod...but the pistons get a lot more expensive.

Your 650 Holley is going to be too small for that engine. A 383 or 400 is going to want a minimum of a 750 or 780. Order the 750 ProForm body when you do the engine build.

Consider going to a Victor JR. You will have more than enough torque with the 400 on the low end...in fact too much. A Victor JR will build more HP.....with minimal loss of torque. With that many cubes you should have no driveabilty problems.

Go with a Hydraulic ( or Mechanical )Roller cam. Don't bother with a flat tappet. Big lift flat tappet cams run the ragged edge on durability on the street. Very hard to keep the lobes and lifters from failing. Lack of oiling at idle is the biggest problem, along with the high pressure springs required to control the valve motion. A hydraulic or mechanical roller is just so superior in every respect that I would not even consider buiding any HiPo engine with a flat tappet cam.