J Heads

Dave, the 268 cam is mild for a 10 to 1 340, with good heads. I agree with Mopar on this, Also not ALL stainless valves come back cut. Check them. 340 + .030(344.5 CID), 10 to 1, 1 3/4 hookers, bowl ported, gasket matched 915's(J) heads with stainless, 2.020/1.600, Air Gap, 750 (3310), with spacer, camshaft range, 274-280*, 230-235* @ .050, .520 lift, (to give a true lift of .500 at valve installed (hyd.), you would need .540 lift to achieve true lift of .500 at valve with mech. (solid) cam, true 1.5 rockers. Also, Use file-to-fit rings, .005 oversize (4.075), and gap them yourself. Always good idea to do this even on street rebuilds. Don't build a new engine with 100,000 miles on it. Most pre-gaped sets will measure gaps in the .030 range, I have seen sets as large as .040 before,(extreme cases). All will depend on what finished size your machinist leaves you. If you gap them yourself, you control true ring gap. This combo with 3.91 gears, will be good street package that will behave well on the street and strip, and can get in the 12's with good tuning. Take your time, select good matched components, pay attention to detail, and check EVERYTHING, (clearances), don't assume anything. The machine shop will tell you "it's clean" ... ok, but clean it yourself, clean everything several times, and when you think it's clean...clean it again, no such thing as too clean of an engine. Sorry to writ e a book here...but basics are often over looked. Good luck Dave. E-mail if you have questions. Terry.