109 vs Stage II Parts Interchange

Hot Air

E85 and S.E./Carolinas Moderator
Staff member
Joined
Nov 11, 2002
I'm a newbie to Stage II parts. Will anything from a 109 block fit a 4.1 Stage II block?
Conrad
 
Yes but why?????:confused: :confused:

The:
-Crank
-Front cover
-Heads
-Flywheel
-Cam

will swap over

The basically everything will swap over except for the pistons and rods.

Another thing that you have to take into consideration if the Stage block is on-center or off-center. This basically means that Buick shifted the one bank (cylinders) .120-.125 to put the rod in the center of the piston pin hence "on-center". I believe the driver's side bank got moved forward, I think.

With the on-center block, the oil pan, exhaust manifolds/headers and intake must be on-center specific. Yes, stock production parts can be modified to fit. Also the production brackets can be made to work on the on-center block.

You must make a decision on which oiling system you are going to use.

I might have forgot some stuff, probably others will chime in.

Billy T.
gnxtc2@aol.com
 
Everything will interchange, assuming it's off-center. Including rods and pistons.

On-center needs a specific intake, or some grinding on the ports and bolt holes, as well as on-center rods. Plus the front conver needs to be milled
.120. Oil pan works on either, as will headers.
 
Guys,
Thanks for the info. I have purchased a on-center block. Trying to determine what I can remove from my 109 engine. Sounds like the Comp 212/212 hydraulic roller cam is about it. Guess I can sell my Champion iron heads and purchase a set of 14 bolt aluminum Champion heads. Then I will need a new forged crank, good rods and new forged pistons.
Conrad
 
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