I can't argue with that.
I will have to talk to Mike.
I have a month or so before I have to start assembly.

That's one of those trade-offs w/ using most -- if not all -- of the fast-rate-of-lift .904" flat-tappet profiles. The .875"-type SFT I ran on the street was much easier on springs and still ran hard. Faster isn't always better.

Never have been sure how "big" that COMP 290/.650 SFT really is compared to other cams. By the time you factor in the recommended .030" lash (IIRC), it's going to loose a lot of effective duration, not to mention .030" net lift over advertised. I know they SOUND big at idle, but...

Ive ran the hughes springs on a standard MP cam and they were done after one summer, maybe 50 runs. On a faster lift ramp, they would even be worse. Hughes springs suck IMO

Dwayne/Fast, Kind of interested on your thoughts on this.

I ran the Comp 290/650 in my 3000lb all iron 440+6 bottom end based Cuda, 14x32's/4.88's/4800 stall/Ladders/coils.. albeit without really enough CR (10:1)as the planned 12.5:1 upgrade never happened but it still ran great, I liked it a lot, ticked over at 900rpm, seemed quite docile to me and it pulled really strong at the top end, I just needed more cyl head to make decent power, think you'll like it in your combo.

The last 2 440-powered cars I remember at the track that used the COMP .650" SFT sounded "totally wicked!" at idle... but weren't any faster than my 440-powered junk running cams with about 25* less duration at .050". It seems far better suited to big(ger) displacements that can actually take advantage of the extra duration.

I have the Comp 23-634-5 stick in the Arrow. It's the .650/.630 split cam...before that I had the .650 ......so far so good. Pulls well and the car is deadly consistent.

No way no how would I run the comp 290/650 lift with your 11.1 combo.

Oh yes, it can be argued.

It will run no faster then using a mp .590 I bet, with a lot less manors. kinda like Brad h pointed out. His cams were even smaller.

No on the MP .620
No on the comp. 290/.650

Use the .620 w/1.6 rockers = .661/275+@.050 with your weight/tyre/theoretical hp combo and 4.56's you'll be turning around 7k in the traps with slip, 4.88 will be near 7500 which would test even that cams abilities at the stripe.....2c's

you could also have a read of this talking about the 290/650>

https://board.moparts.org/ubbthreads/ubbthreads.php/topics/889058/2.html

His engine is a 4.15 ,11.1 stroker. Its sweet spot wont be anywhere near 7000rpm to 7500rpm. I will say it one more and last time, throw that mp .620 away.

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For what you have in your corral, the MP .590

Well you may be correct, however I was basing my opinions on his 3000lbs/4.56/32.5" tyre combo and his 487ci and expected flyhp which should be in the 660hp range in which case he WILL be trapping at around 7k w/slip.

From my experience with that .590 cam on a friends 440 Dart with 12.5:1, 4.56/31's and similar cfm heads as the op and with a 1050 Dom, 5000 stall, the car would slow if shifted over 6300 and it was done at 6750 in the traps, with the ops bigger stroke@487ci he has it won't help in my opinion.

If a change was made to 4.30 gearing then yes perhaps it would work, but he has run that cam in a 440 and was asking for an improvement I believe with the new combo....Anyways I'm sure he will be in the 9.5's or better.

Sell the STR and go roller now.

For the record, I like the MP620 cam in something with small-ish heads, a lot of stall, a car thats not too heavy, 1.5 rockers......and at least 13:1cr.
As measured, it's 283@.050....... So it's a big cam.
That being said, there's almost always going to be something I like better for any given combination.

I generally prefer some upper rpm stability over super fast ramps, unless there is a "need" to get every last HP out of the build.

For the OP's proposed combo, I'd use something around 270@.050, and stable lobes where you could maintain decent valvetrain control to 7000 or so, running 1.6 rockers with "normal" spring loads(150/375-400).
Lift with 1.6's would be low/mid-.600's

A fast rate .904 cam would likely make a few hp more, but will be a bit tougher on parts.