Multi-disc clutch Tech page.
All Ford 302/351/5.0l pushrod engines have the exact same crank flange and rear engine block to bell housing geometry.
All pushrod 5.0L late-model Mustangs with a manual transmission use a 157-tooth ring gear, as well as a specific bell housing and starter offset. Installing an early 302 or 351 based small block engine into a late model Mustang requires using a late-model Mustang style bell housing, block plate, flywheel, and starter. Doing so will correctly match the ring gear offset to the starter.
Ford small block engines were all externally balanced, with weights attached to the flywheel and harmonic damper/balancer. There are differences in the engine balance used.
- All 1981-2004 302 (5.0L) pushrod engines have a 50oz-in imbalance.
- All 1968-1980 302 pushrod engines have a 28oz-in imbalance.
- All 1969-1997 351 pushrod engines have a 28oz-in imbalance.
Some high performance engine builds are internally-balanced by adding heavy metal weights to the crankshaft counterweight. This is done to reduce torsional flex and resulting stress on the crankshaft. These internally-balanced engines require that there be no weight on the fly wheel and harmonic damper/balancer.