71 340 bored 30 over with JE Domed Pistons. "J" big valve heads with shaft roller rockers. What is the mechanical and roller of choice. Been running 590 Mopar. Looks like a bad lobe. There are so many on hear with some good advise I will appreciate and consider everyone's opinion. Thanks for the help.

Got any idea what the heads flow and what rpm do you
plan on turning

They are 915 "j" heads with some home port clean-up. Typically 6500 through the lights.

Its hard but try not to over cam. My sons street legal duster (360)runs 10.50's and my 408 duster (strip only) ran a 9.98 and both are using a 520 solid cam from Racer Brown.

just curious if that's the ST-21?

Thanks for the information guys. Are your racing Hydraulic, Mechanical or roller? Any more recommendations?

My 340 w/J heads liked the STH-42(Hyd. version of the ST-21)

I'm putting the same one in my 374.

Thanks for the reply and the Duster is a race car only no street time.

If you're willing to change the springs and such a roller will make more power.

If you want to keep your current valve springs that will dictate how aggressive you can get with your camshaft. Run good oil with whatever you choose.

The Comp solid grind that is 255 @050 intake and ex is one of the best small block stock type head cams out there for 1/8th mile it is amazing! I put it in a 360 at 103 and it will yank the spit out of your mouth on the leave. Think it is 540 lift--a REALLY good grind. My old heads maybe flowed 225 intake so nothing great and my Duster would run 6.90 1/8 ths and that was with an RPM dual plane--It would have all it wanted in a 1/4 mile run and would have liked an open intake but for 1/8th it was just killer! 106 LSA so in at 103 and it sounded like a top fuel car at idle, I always used 1.5 rockers -- Rollers in a SB can be a Pain--ask around about what lifter will fit the block and if you have stock length valves you really have to sink spring pockets , use 10 degree titanium retainers, etc to get a decent spring on it as installed ht is so short

Check out the lunati voodoo 60442 solid cam. Makes big power

Call these guys and see what they recommend.

Im very happy with their solid flat tappet. It picked up ET over a similar Scott brown cam.

http://www.hughesengines.com/Index/index.php