Wondering what upgrade would yield more HP gain, roller rockers or 2.5" exhaust system (with or without X-pipe).

Have: stock stamped rockers, 2" dual exhaust thru mufflers

Car: 71 Challenger w/318 recently stroked with 4" crank. Performer heads, MP hydraulic 474/280 cam, air-gap intake, 750 Performer carb, Summit headers, 10:1 CR, 727 TF. Used mostly as cruiser (3.23 gears, 2500 stall) but like to run occasionally at strip. Usually shift around 5K, still pulling hard, 12.95 ET.

Like the torque monster, but wouldn't mind a little more HP. Heard the rockers yield anywhere from 10-25 HP over stock, have no idea what the exhaust would do. Love to hear other's experience.

Thanks in advance.

Roller rockers will yield NO real performance advantage. Go with the exhaust. This is not just me saying this. It was also in one of the the mags.

That hp claim has been the claim for chevy motors forever. Your cam is mild and the roller rockers are not $$ effective.

Do you have headers already? If not, they would sure sound sweet and help with power more that roller rockers. What is your initial and total timing set at? Have you run the car with a wideband A/F ration monitor on it?

a good mandrelbent exhaust is what i would go for with those options, a dual 2½" with good flowing mufflers will be enough to suport a 12second car and still be very friendly on the street, if you have future upgrades on your mind you may want to go for 3" even but that will be harder to quiet down to a nice tone when driving.

my vote is for exhaust.

I'd go with a 2-1/2" mandrel bent system and some hooker aerochamber mufflers. You could probably go with 3", but it would be louder.

I don't like the way the x-pipes sound, but they supposedly work better than the h-pipe setup.

You already have headers on there, so up grading to more expensive ones is not going to net you any power increase in your situation. Neither will wasting money on roller rockers when stockers are doing the job just fine. There is no hp upgrade to roller rockers, they are just more friendly on valve guides when used with high lift cams. They also offer a truer rocker ratio, but not worth the $$$ for you. If you want a bolt on upgrade that will do something, save your $ for a used centrifugal supercharger.