"car, truck, boat or tractor..
"car, truck, boat or tractor... the camshaft opens the engine's valves.
The distributor times the spark. And a 4.3 requires the spark at different times than a 3.8 due to the offset crank journals and "semi-even" firing order of the 3.8
The 4.3 is an even-fire V6. 120 degrees X6 = 720 degrees.
The 3.8 fires at 108, 132, 108, 132, 108, 132
I thought your exh. manifolds were toast.
The factory 3.8 manifolds will not fit 4.3 heads.
The Osco brand center riser manifolds will fit either 3.8 or 4.3 heads.
NORS 3.8 short block $999 + ship. .030" over - new pistons, std. main and rod brgs. , brass core plugs. Everything magnafluxed, honed, crack checked and returned to factory spec.
Block is in the factory OMC shipping crate."