I'm late the party but I did notice nobody asked him exactly what his "stock motor" consists of. Consists as in what the short block is built with and what heads are on it now. If it's a stock 70's build, that's one thing. If it's a later model roller 5.0 "stock build" that's a whole 'nother animal. Making recommendations based on what he's told y'all is foolish without knowing what he's got.
but... maybe they decided to build him a ringer of a motor with forged 5.0 pistons having no valve reliefs, gapless rings, zero-decked it for some GT40P heads with Ford Motorsport springs? errr, wait.. maybe that's more along the lines of a CUSTOM rebuilt motor? brings to mind that funny old rhyme.. "how much wood can a woodchuck chuck?"
We did a rebuild using a comp cam (wasn't to radical) had some very good early cast 289 heads that had been worked. press in studs, ehich were converted to screw in at time of rebuild. since it was a daily-ish driver we didn't want to go too crazy. however, the stock rockers didn't take the lift too well and on the test ride snapped 2 of the studs. :0 problem was the slot int he rocker wasn't long enough to accommodate the lift. replaced the rockers with come cams roller tips that have longer slots, new pushrods and a stud girdle. been 3 years been a solid occasional driver for my wife. so , if you have dinosaur hi-po parts like we do, make sure the lift is compatible with your rockers as well. BUT, as said, if you are building another rmotor, leave the current one alone
As I said before, "rebuilt stock 302" could be anything 40 years after the car (and heads) left Ford. You don't know who built it nor what was used in the rebuild. And the OP hasn't said either.
Very real possibility here. I've taken apart a dozen 302's that were complete mysteries as to what was inside. And the people who I got them from had no clue. And I'm not even going to mention the half dozen "Boss 302's" that were anything but when I went to investigate them.
As usual, I was just being a smert-ass. But you do bring up a valid point about the mish-mashing of parts tossed into "rebuilders specials". Still seems highly doubtful this motor is much higher than about 8.8/1 SCR but as you say.. stranger things have happened. Head casting numbers would help spell it out loud and clear too. With the typical crappy single or two point valve seat cuts many plain jane rebuilders use.. most smog castings flow less air than your typical water faucet flows water. lol
Sorry should have been more clear about this, the engine is a rebuilt 70 block with all stock parts. Aside from the intake and carb you can anymore stock then that,
True IF you're building from scratch but more often than not, what's actually inside is a total mystery... No need for a .600 lift cam when the stock heads quit flowing at .500... A cam is upgrade is most always going to be a trade off, to get more power basically the RPM range is move higher so bottom end will suffer... A mild performance/RV cam will almost always give a noticable boost and not break the bank... As long as one stays around .475 lift, stock springs in good condition generally work...
If you have the 65 hds then they do not have the thermactor tube bumps in them.Pocket port them & put 1.5 chevy ex. valves,& 351w 1.850 intake valves & if you said they already have screw in studs you would have a decent set up.Obviously,not 185 AFRs,but something that will make you a little xtra power without breaking the bank.I have this exact set up that I`m going to sell pretty soon to get the money for my pistons.
Look at the passenger side head at the corner, next to the valve cover. If the heads are mid 80's-up there will be one of the following : "S" "T", "GTP" or "GT" . The "S" head is the E6SE casting, the "T" is an E7TE. If there's none of these letters, then they're earlier castings and can only be Id'd by taking them off the block and looking under one of the intake runners of the head . Pre 78 heads had pressed in rocker studs, post 78's had pedestal rockers.