difference between on center and off center


runs with scissors
May 26, 2001
lagrange, GA
Sounds WAYYYYYY too complicated for absolutely no reason whatsoever lol. Just center everything and be done with it lol. It actually sounds like more work to go out of your way to ensure it wasn't on center lol.
Because they'd be back to having a rough running odd fire engine that wouldn't sell as well.

It was less work to flat spot the rods and use the same block and heads. It was defiantly a compromise decision that they got away with.


Well-Known Member
Staff member
May 28, 2001
Bergen County, NJ
Billy, is this for StageII heads when you are talking about headers, rockers and lifters? My Dad had a 3.8 StageII motor and went to a 4.1 on center StageII and aside from the rods, pistons and intake. The heads, headers, lifters and rockers were transferred over.
No, Stage heads are whole different animal.

When using an on-center block, the banks (1-3-5) and (2-4-6) are shifted approximately .120"-.125" from each other. The lifter bores don't move. Either you're going to need offset lifters or offset rockers/machine the heads to get the valvetrain geometry correct. When you bolt the heads on, the banks are shifted. The headers need some type of adjustment to make up the difference. The TA headers already have the adjustment built into them ie: V-bands by each header and slip fitting on the crossover.

Billy T.