so shortly i will pull my 4.9 out to rebuild it since i'm blue smoking. Its in an 86 f150 4x4. I've already put an offenhauser intake with a holly 390 cfm and headman headers on the truck (someone got leadfoot after this and ran the truck a little hard ) With the engine build i want to get the most power possible and keep duribility in mind. At this point for upgrades i'm looking at a cam, roller rockers, and 240 heads. any more recommendations to get more power out of this engine?
From my research and no actual experience a freshly rebuilt 300 with a Offy dp, Holley 390, roller rockers, 9-1 cr, longtube header, good exhaust, and an isky mile a more cam are good for 225hp and 300ft lbs of torque. Fordsix.com the guys over there can tell you more then me
There's no real performance advantage from roller rockers but they're probably the spiffiest looking $250 you can put underneath a valve cover.
And to that end, without the need for studs onto which rockers are fitted there's no real advantage to a 240 head if you're going to rebuild the bottom end anyway. You can raise compression with the piston (taller compression height or smaller dish/flat top) or by having the block decked.
Then use the $400 you would have spent on roller rockers and a 240 head to have some porting and a 3-angle valve job done on the head you've got now. Outside of the stock intake/exhaust manifolds the head is the single biggest limiting factor on a 300.
Otherwise some ARP rod bolts are cheap insurance. Spend a little extra to have the rods and pistons balanced, too. And find a machine shop you trust to do all the work.