I’m curious what the numbers are on a low deck 496
Kinda like the 496 that 440 source sells. 4.310 bored 383 block using there 4.250 crank

It depends, of course
AKA, the heads, cam, intake, exhaust system size, carb sizes and actual weather that day will determine how much power it can make.
My first pump gas 400 stroker motor made 612HP at 5500 RPM and 644 Ft. Lbs, at 4500 RPM with a set of mildy ported big valve 906 iron heads with a custom ground Comp Cams solid roller cam with 260 degrees @.050 on the intake lobe with .420 lobe lift and 266 degrees @ .050 on the exhaust lobes with .409 lobe lift ground on a 108 LSA installed at 106 intake lobe separation using a low deck dual plane six pack Eddy intake with 1970 440 six pack carbs
that motor exceeded my wildest hopes, it flat work well
i hope yours does too

Yes I understand. That’s awesome numbers. I’d love to have that torque

Heads, cam, intake, headers make the power so you have to pick the parts you are going to use before you can predict the power. 500 hp is easy with a 500 inch shortblock. If you want 600 hp then you should use Trick Flow 240 heads and pick a cam that will hold power a little longer. If you want 700 hp then you need to move up to a MW head like the TF 270 or an Indy EZ head. You'll also need a bigger solid roller cam and a good intake, correct headers and the correct carb.

Gotcha. I’m currently with a set of 440 source stealth heads
So I’m only want to kinda Mimick the 612/644 build from above.
Or any other build that is similar.

493-499 rb being the older/higher usage combination has near endless examples of builds out there, low decks are
much less commonplace.

Is this for the new truck?
I saw the post about it, looks great and that is cool you were leaving the big block, as I was expecting it to be converted to a hot Gen 3 immediately
(that would also be cool, but definitely much more expected considering the source!)

I hope you checked out the street 496 post. Not a low deck, but pretty close to what you are describing. Very good numbers.

440Source heads will limit you to the 500 or 550 hp range unless they are reworked by a pro.

what about victor standard port heads? What is their HP limit? I had mine just "cleaned up" and then flowed. they did 325 cfm @ .550 he didn't flow any more lift....

the heads will be finished by craig gallant from gtp.
im liking the numbers from the 440/496 build.

We are planning a similar 383/496 build with a 440 source kit. Trick flow 240's and track heat intake. Waiting on machine shop to confirm the 383 block will be good to go before ordering rotating assy. Got the heads last week, Dwayne picked the cam. Solid roller 262/260 .631 with 1.5's. 950 etc.... Should be fun. That street 496 post is pretty dang impressive! Especially considering flat tappet and pretty small carb. But I've always liked low decks. Build your low deck and dyno it for us so we know! lol...

I have built at least three mild street 4.25" stroke 383 engines. They work just fine. The most recent was with 452 iron heads with stock valves, homeported, 750 vacuum Holley, 1 3/4" headers, 0.5" hydraulic flat tappet and an Edelbrock CH4B ancient intake. It was actually pretty strong making over 490 hp and 600 ft-lb. The others have had aluminum heads, source and E-street which are pretty much the same. All with flat tappet hydraulics and stock rockers etc. They have all been pretty close, between 490 and 530 hp. And a tremendous low end with over 500 ft-lb at 2200. One was later converted to Victor style heads and a solid roller. I think it made a little over 600 hp naturally aspirated, still with the same relatively low CR short block. Basically you can do pretty much anything with a 383 that you can do with a 400 or 440.

Don't forget that all the 383 blocks have the same thin main webbing just like all the RB made before 1973 had
if you can find a decent 400 block build that after having it sonic tested well

Exactly. Also as has said, better heads. Tunnelrams make torq...

I have built a couple of 512 400's from 440Source and man they run...You can make darn near 800hp if you want to. Not sure on longevity, but use the girdle and keep the revs down, and it should last a long time.