Trying to decide which cam to use before I put the motor back in my car. I tore it down to swap in a set of 69 pistons which bumped compression just over a point. That being said, combo is listed below. Give me your thoughts on which cam to put in.

1973 GTX @ 3550lbs - Driver weight

440 with Standard Bore and Stroke:
9.25:1 compression cast pistons
906 heads w/ 2.14 / 1.81 valves and template porting
M1 intake currently but may switch to Tunnel Ram...
Holley 850
1.5 Rockers
1 7/8 Headers
3500 stall JW converter
4:56 Gears w/ 30" tires
12.50s @ 107 was about typical on a good day before piston swap.

Cam Card pictured is for the Hughes and pencil marks are for the MP 296/557, disregard valve lash, MP was listed as cold setting...

Thoughts?

When I went from the 292/509 to the 296/557 with the 8:1 compression I gained nothing FWIW...

Run the .557 , the Hughes HTL requires PERFECT lifter bore to cam lobe geometry , if you haven't had the lifter bores bushed you will 99.99999999999999999999% have problems with that cam.

The 557 cam,in reality is 257 @ .050. It is quite a bit larger duration wise than that Hughes grind.
I have run several Hughes cams and never had an issue with non bushes lifter bores,I happen to like Hughes cams.
If your choice is down to those two,the 557 is a better fit.
I spec'ed a custom for my brother in his 4000 pound Road Runner with a stock bottom end 440 andstock Edelbrock heads that runs 12.20's. It is closer to the 557' in duration,but a tighter lsa to help with torque and get the heavy car moving.
Hope that helps you a little.
Keith

THANK YOU!!!!
Both the articles that I have in that issue were submitted several months ago.
I sent two more about a week ago,so it may take a while to see them.
Keith

The MP 0.557" solid cam is a decent street/strip cam. I run mine at slightly tighter hot lash (~0.25").

However, I think the Hughes cam is a better fit for your application. But as John points out, the aggressive lobe profile needs the lifter bore geometry to be good. It may not need bushing, but some careful checking by somebody that knows what they are doing is recommended.

After thinking on it for a bit, I think I'll put the MP back in for now. Thanks for the input guys. Next question, should I advance it or put it in straight up?

I've heard half a degree of duration per thousandth of valve lash. So yes while the mp .557 is 256@050, once you take into account the wider valve lash its more like 252@050 when compared to that hughes cam. Going by hot valve lash figures. IMO not enough of a difference to warrant changing cams.

Ive always had good luck tightening up the las on the MP cams to .022 on both lobes.
As far as where to install that 557 in your car,I would probably stick with a 108 installed centerline. You can usually get a good gain in torque down low advancing the MP solids,but with your gearing I think you would lose a little top end going too far advanced. You have enough gear to get away without it.
If you had less gear I would go further,106 or even 104.
:twocents Keith