im rebuilding a 2.8 TBI out of an 86 blazer that has a spun rod bearing

i also have an 89 2.8TBI out of a firebird with a blown piston.

will i have any balancing issues if i were to use the crank, connecting rods, flywheel and harmonic balancer out of the 89 engine in my 86 block? because other than the piston, the engine was in really good shape, i checked the crank and showed no rough spots and measured to specs.

also, will 3.1 heads fit on a 2.8, im pretty sure they fit on all 60 degree v6's.

 

-- Your 89 2.8 firebird engine should have been multiport, not TBI...

I believe that 87 and newer 60* engines are internally balanced and older ones are externally balanced. Make sure to check all oil galleries and main bearing oil holes in your 86 block if you are using it. 86 was a change over year for these engines when they were perfecting it and ridding it of the oiling problems from previous years all the way back to 1980

You can use the block; physically they will interchange

any 87 and later 2.8 / 3.1 / 3.4 heads from fiero, f-car or s-truck will bolt right on and are the best factory heads for your application...

 

yeah sorry i meant TPI

i was just worried i would have alot of vibration or running rough because of the swap, the only difference i can see is the crank, the original one out of the 86 has no weights on it as the 89 does, but i figured using the harmonic balancer and flywheel would keep the same balance as the TPI's

if you guys have any experience with this please let me know.