I don't have a clue,Ron!! That is why I asked..

Cam looked like a really good call
With the limited head flow (340 isn't lot for ~540 cubes) you know it's gonna be RPM limited, that's why I was thinking a 2" x 3 1/2" (like a Pro-parts vs the fenderwell) header might be a great call for an A body. The extra 10 degrees and lobe spread (compared to what you might see in a similar 500" motor) helps pull the power peak higher with the limited head flow. But I think a set of 360-ish ported -1's (with their extra cfm, a bit more port volume AND the better exhaust) would be awesome for this motor, just think, you could run a 337 intake and have a 700+ Hp streetable motor that would fit under the hood. But as Dwayne said, these were the parts Mark had and I totally understand the economics of it. And in an A body I'm not sure you'd have the chassis clearence to run a raised Ex port -1 on an RB block, I know it works with a B block though. But I'm thinking this basic recipie could be a perfect fit for lots of B's and E' that could run a raised port 2" tube header set, or make it a low deck (at least close on the cubes) and run an "off the shelf" 2" header. I certainly understand the appeal of the EZ/EZ-1 with the easier chassis/header fitment, the std rocker offests and conventional oiling though.

As for the torque, Jim I agree but if you consider roll-on power and street "efficiency" for 'real world' driving, that obvious boatload of extra torque below 4000 could still run very decent times even with a much tighter converter and make for a more satifying dual purpose car. The thing I still see time and time again (including several guys on this board who PM me) is guys wanting a 'dual purpose 'car but wind up jumping in the max HP derby, they up the Torque peak RPM and get a vert to match and then the car sits and sits in the garage because it's just not as much fun to drive (again 'real world') as they thought it would be.

Great Thread, need to go in the Archives!!

how fast would you expect a 680hp combo to go at 3450 lbs = 10.0s 9.80s maybe a little quicker ? depend on how well the rest of the car was sorted out.

I would think it could run very low 10's at 680 hp and 3450 lbs. Ron

Based on my own set up, i would say 9.70-90 dependent on converter, chassis.
Mick

Dwayne, I'm assuming the AFR sensors was on one side, correct? I noiteced the AFR and BSFC didn't seem to jive , especially above 6000 RPM Whats up with that , is there a exhaust leak or what Maybe the needles and seats aren't big enough

as for the headers.....they were left over from the previous 446.
they were in decent shape, and werent going to get changed unless the car wouldnt run the number.....which only needed to be a 10.0X in summer air.
the car isnt legal for 9's, and the owner doesnt really have any plans to cross that line.
he would just get a different car and put this motor in it if he wanted to run in the 9's(or quicker).
other than the 6 pak style hood, its an all steel Dart with full interior and stock seats. roll bar, Dana, and the owner is probably around 300lbs.

when he was talking to ATI about the converter, my choice would have been a 9". they assured him they could get an 8" tight enough, and that the efficiency would be better.
the target stall speed was 4800-5000. it flashes 5400. its been back once, still flashes 5400.....and now they say its basically as tight as they can make it.
the good news is......it doesnt slip much on the top end......and it leaves great.
typical summer ET's are mid-9.80's(the local track isnt much of a stickler for having to have the right paperwork/equipment to run in the 9's).
as i recall, speed is in the high 133/mid-134 range during the summer months.
60' times are usually around 1.31.

best ET was a 9.66 this fall, 137mph and its gone 1.29 60' a few times.
also....3 wins this season

Dewayne, the title under your screen name is perfect and accurate. Jim

from wallace. i used 9.66 134 mph 3450 weight

Your HP computed from your vehicle ET 756.44 flywheel HP.
Your HP computed from your vehicle MPH is 664.77 flywheel HP.

maybe that converter has it ET'ing very well the 60s sound really good

when i do my car, the numbers are much closer than they are with this car

the 9.66 was at 137mph.
that should make it closer.

also.....the thing has no top end really.
its going out the back at 7000-7100.....and its just flat up there.
at 7000rpm, with the car headers.....its probably only making around 620hp.

that bumps it to 710

what does the moroso slide say for the combo? i would like to know if wallace is way off

With the torque curve of that motor, I would want a 9" vert too.