Spookie's stock 40 year old 88,000 mile 302 engine is tired and is on its way out. Should I rebuild the original engine stroking it and converting it to a roller motor adding fuel injection or do the same rebuild to a newer roller engine with a one piece rear main seal? Should I just buy a crate engine?
Now days it's almost cheaper to buy a roller motor, crate engine. http://www.summitracing.com/parts/FMS-M-6007-X302/
With a crate engine you get a nice warranty. If you do it yourself it is warrantied until you start it up.
You already have one car tore apart and scattered all over your garage. Do whatever it takes to keep you from doing that to Spookie. Knowing what your plans are for the other car, I would just do a basic stock rebuild of another engine and swap them out. Do you really need two high performance Mavericks? Keep Spookie a basic daily driver.
You might save some money by buying a rebuilt roller long block and swapping all the external parts, except for the distributor (gear), from your old 302. Or save even more by finding a good used 5.0 and doing the same. The right answer depends on your budget. I bought a serviceable 5.0 engine for $250. Didn't have any trouble finding one.
Aluminum block 351 stroked to a 427 w/aluminum heads and intake, same weight as your 302. It's easy for me to spend other people's money...
Neglected to mention 50 oz balancer and flexplate/flywheel if you don't buy a used engine with those parts.
Personally I think crate motors are overrated...........but that's just me. I'd by another 302, rebuild it yourself (as long as you know a decent machine shop), put it together yourself while you are still driving the car...............then spend a day or two swapping it out for the original.................I'd keep the original. I'll bet you could do it for under $2k and have a really nice motor to go another 80k miles...............................................IMHO
If you do go the crate route you still need to thoroughly check out the supplier's work. Twice I've bought crate short blocks instead of building my own like I usually do because I didn't have decent parts to start with. On both I found clearance issues among other things that I had to straighten out before use. One place even sent a completely different block than what I ordered!
There is an ole saying that's older than I am.............was true 30 years ago and is certainly true today, "If you want something done right, then do it yourself".