Finally got my sbc 421 together and put it on the dyno

Here are the specs:
4.155 bore x 3.875 stroke, 421sbc nitrous motor
12-1 compression, 5.6 dome
Jones cam (lift.699 int, .659 ext) (dur @seat 316int 320ext) (LS112)
AFR245 unported heads with LGM shaft mounts (1.7 int, 1.65 ext rockers)
Edelbrock 2970 ported
Mark Whitner 1050 dominator
Used 1 3/4 dyno headers

With 110 octane fuel made 586 TQ @ 5200 and 686 HP @ 7200 with 34 degrees timing
https://ibb.co/nBMmpc
https://ibb.co/m2Kgpc

With 94 octane pump gas made 567 TQ @ 5400 and 657 HP @ 6500 with 30 degree timing
https://ibb.co/e3A1Nx

Overall really happy!
https://ibb.co/csTP9c
https://ibb.co/eQPLhx

Can't wait to spray a 300hp shot to the engine
I have to install my powerglide 1st before I spray, no way my th350 I have now will hold the power

 

Very nice. I am curious is the listed lift with or without the 1.7 rockers figured in? In other words is the shown lift with those rockers?

 

Yes, the lift is shown with the 1.7/1.65 rocker

That is what was advised from LGM and Mike Jones

 

Pretty solid for a nitrous motor

 

I like it.

Also proves what Smokey Yunick said: costs 5 times as much to go from 500hp to 570hp with the sbc.

 

Nice numbers.
Was that cam spec'd specifically by Jones?

 

Maybe to 670 lol. Todays head choices are much better than days of old. Up to 600 can be fairly easy to achieve at 400-434”.

Goin over 600 starts getting expensive and need more tricks and special treatment to do imo

 

I guess I should have qualified that with reliable 570hp. It takes good parts to keep a motor together making that power.

 

Yes.
I talked to other cam companies as well.
Mike came highly recommended from other guys in the industry.
Plus, I have a 50mm roller cam tunnel in my Motown block, which narrowed down my cam options

 

Agreed.
Anything over 600hp meant me getting an aftermarket block, along with nitrous.
I could do it with a stockblock, but not reliably and less longevity

 

Nice numbers!! Think there may be a couple more HP in a stepped or larger header?

 

On motor, I think the 1 3/4 header is almost maxed out

I have 1 7/8 Ed Quay headers on my car so that'll be better suited once I spray.
But yes, I am curious if a stepped header would help once on spray

 

What lifters did you use for this build ?

 

Crower 66292H