I am dismantling my 300k-mile old 302 in favor of a newer block (60k miles, new rings, bored .030 over so it's actually a 5.0) and removing it very soon. I took the heads off, and an explanation of a lot of my tuning problems with both carburetors and throttle body injection was found: They put it together with two different heads! One's a 289 head, higher compression, 1968, and the other is a 302 head from an unknown year! One side always ran better than the other and I always had mix adjustments that were totally different for each side. Hopefully a lot of my problems will be solved just for the reason that I will be using matching ported C9TE heads that I'll be getting machined for 9.5:1 compression. I will also be installing port injection via intake manifold from an '87 Thunderbird 5.0. Don't buy a cheap rebuilt engine.
Am I reading this right? the crappy engine went 300,000 miles? not too bad Id say even if it was hard to tune.
A 68 289 head is pretty much the same head as the early top mid 70's 302 heads. I doubt that was the problem. And there's no way to know how one "side" of the engine runs better than the other. There were two basic chamber shapes in those heads, one looks like the C9TE head, then other is more "triangular". As for cheap rebuilds, that's a crap shoot. One of my better builds was based on a $350 (exchange) reman roller short block.
Don't feel too bad...I just got raped by a shop in Lewisville, Tx. for a motor rebuild. Was supposed to take 7-10 days...instead took a month and a half. Most of the repair work that was supposed to take place was either not done or done poorly...the motor reinstallation was a complete mess and the car still doesn't run right. They didn't even perform the rebuild themselves (sent it out to another guy, who actually did a good job), but they did the removal/reinstallation/retune. The tune was crap, vac lines not connected, very rough idle, no power, leaking oil and power steering fluid now, put the old thermostat (stuck open) back in, loose torque converter (think they might have done this because wasn't loose before), painted carb had sticky linkages and didn't work right along with an unbalanced/horrible tune, they damaged my hood in a few places, timing was off and TDC/Dist/timing don't match up, they put damaged plug wires back on the car, didn't replace any wiring/hoses/vac lines and a quite a few other things......all-in-all, a complete cluster f'. To top it off, I think they might have damaged the rebuild themselves because the mechanic who did the work admitted he didn't know about old cars and they were having blowby and timing issues when trying to get it running again...wondering if they blew a gasket because I can't get the car to smooth out and stop fouling cyl. #8. Like I said, dont' feel too bad.
That's why I've decided to do all engine work myself (except machining), not to mention the fact that I'm running MegaSquirt. The engine went that far after one or two rerings, but other than that, yeah! My brother (the previous owner) didn't change the oil very often-- 10,000 miles or more without a change in one instance-- and I've had oil pressure problems with this motor since he gave it to me, so that's the main reason I decided to replace the block.
