tanager11

I am in the middle of figuring out all the details for an upcomming swap and need some help/verification on what Flexplate/Balancer I should be using.

I am going from a L03 to a low buck GM Crate (P/N 12499529).

Can the flexplate and balancer from the L03 be used on this new engine? I dont "think" so but can anyone help shed some light into this for me.

Thanks in advance
Dave

SR-71

Balancer -- Yes.
Flexplate -- No.

This engine is internally balanced, but has a 2-piece rear main seal. The L03 is internally balanced with a 1-piece rear main seal. The bolt pattern on the rear of the crankshaft is different. You'll have to get an older-model flexplate. Otherwise, everything else should be fine.

The intake manifold will probably need to be modified to bolt onto the heads, if your original valve covers are center-bolt style, which indicates a newer-style head with different intake bolt angles. It's just a matter of re-drilling some of the holes in the manifold.

tanager11

Thanks for Clarifying that for me SR-71...much appreciated.

Already went through that with the intake when I swapped on some 416's a couple years ago...so my manifold has been altered to bolt up to the older style heads....but thanks for mentioning it.

Dave

five7kid

iTrader: (14)

Your 416 heads would work better on that engine than what comes on it.

tanager11

Ya that is what I was thinking about the 416's...especially since they are ported and probably only have about 5,000 on them since a rebuild...but for the time being I am just going to use what come on that new engine. Right now I just want to get the car running and reliable once again...then a couple years down the road worry about squeezing a bit more performance out of it.

five7Kid--> With those 416's on the above mentioned engine, is there really any dissadvantages to using those 305 heads on the 350? It will probably raise compression I am assuming...any ideas on approx how much?

Thanks,
DK

five7kid

iTrader: (14)

416's would bring compression up to about 9:1. Still very pump-gas friendly, could probably still run regular in it.

As for 305 heads on a 350, that's what I'm running (although not 416's).

The heads would be easier to put on when the engine is out of the car. But, I do understand the time thing. And, unless you've got headers, and do what's required to optimize the TBI, you aren't going to get 290 HP out of the engine, anyway.

For the record, the flexplate you will need is the same as the '82-'85 f-body V8 application, 153 tooth, 12.85" diameter, such as a Pioneer Products FRA112. $18.99 from www.partsamerica.com. Their "heavy duty" version is FRA112HD, $69.99.