Years ago I installed an old Comp 280H cam in a daily driver because I had acquired it with a bunch of parts cheap, now I'd like to gain a touch of power for an index street class, I now have a Mopar .484 I've never used, kinda like to keep it hydraulic for now, I have others but all solids and would need to change valve springs for them. Car will do the 7.50 index in good air but doubt it will in lousy air...

I think the rest of your combo might play a big factor, in the early 80-s we would drive from lower detroit to see friends and hit the brackets at avvila and bunker hill and with the 284/484 a 3k vert, 3:55 rear and some small diameter dirt track like slicks (put on there) would run pretty consistent 7.40s, most the time it was dead on 7.47.

The rest of the car was just a re ringed 360 and a ootb shift kit.

In my setup I forget the 60 ft times but its really what got the 7.40s to work because I never recall the car pulling very hard, just would hook and launch well.

Friends used to run the comp cam and it never seemed to do as well.

Is this a SB or BB motor ? Also is this a older Purple Shaft street Hemi grind .484 lift 284 duration cam or one of the newer grinds? If it is one of the older version for BB motors I hate those no good rascals, nasty sounding idle, no vacuum at idle and no low end power
If it is a SB motor, I have no real experience with them

Cab, It's a 440, how do I tell if it's the older one or newer? I think it's the newer...I bought it from a member here a couple years ago.

I think you'll find the numbers at .050 are drastically different, meaning the mopars cam has faster opening rates than that Chevy cam. I think the 284 is 241@050. The 280h is probably a lazy 230.

The "real" difference in how "lazy" the comp is in comparison to the 484 cam are the differences in the checking height for the advertised numbers.
For the Comp it's clearly stated in the lobe specs that the advertised number is taken at .006" tappet lift.
I haven't personally measured a 484 cam, but the 509 cam I measured, that supposedly has "292" deg advertised duration actually measured 305-306 when checked at .006 tappet lift.
Within the same lobe family as the 280h, a lobe with 305 duration at .006 gets you .525 lift with a 1.5rr, and 253 @ .050.

I doubt the 484 cam actually has a lobe that's any faster than the Comp 280H....... It's just a bigger cam(longer duration), and that's where any power gains would come from .

"If it were me", and I wanted to make a real improvement in performance over the 280h, I'd put a solid in it.

To make any kind of valid recommendation for a cam, solid or hyd, I'd want more info about the overall combo.

Dwayne, It's a stock 71 440(9.2:1) with ported 906 heads, 2.14 1.81 valves that ran(heads) 6.40's/10.20's in my old 68 b'cuda, choice of 1.5 Harland Sharp or 1.6 Crane rockers, currently using the 1.6's with the 280H, Torker w/850 dp Holley, 1 7/8 Hookers with 3" race mufflers and 3k B&M converter. 4.10 Dana & 29x11.5 Hoosier cheater slicks, pump gas daily driver. No roll bar, therefore I don't want much et improvement, 7.45et @ 90mph in good air now, would like to do that in crappy air. 65 Coronet @ 3,420#. Have much better combos once I go with rollbar... I have a bracket car to go fast, this is just simple, fun and cheap driver. Thanks for all input.

If you search this site for how fast on a 282 484 cam you will find alot of BB combos vs other cams... good info, many pages.

https://board.moparts.org/ubbthreads/ubbthreads.php/topics/82240/pros-and-cons-for-284-484-cam.html

If you have enough spring for it, and since you don't need to ring it out tight at the end of the 1/4, I'd suggest the Comp XE285HL with the 1.5 rockers....... And maybe a RPM intake.