Got it running and took it around the block but it backfires alot. Only been able to get up to 40mph and doesn't have good acceleration. Anyone know what the issue might be?
Out the carb? I had same issue but on a rebuilt engine. Was told to use a 351 firing order and that was the problem. Needed a 302 firing order.
more info needed for armchair analysis - new problem or new to you vehicle? ... . 6 or 8 - firing order is simple to check as mentioned. . Ignition timing , distributor cap etc condition is suspect. . if been sitting - stuck valve or more serious internal problems . pulling plugs and static compression test is likely next ... . have fun .
If it's backfiring out the exhaust, a defective A.I.R. diverter valve can be the cause. A carb backfire is usually ignition timing related...
It should be on intake, though not always, with cam swap may not be correct anyway. Verify spark plug wires are in correct order. If so, 302 & std 5.0 order is 15426378. HO 5.0(1982 & later) & 351 13726548. Swap 5 with 3 & 4 with 7. If that fixes problem great, if it's worse, you have other problems.
