GM Performance Parts BBC Block Question

Jeff Jewell · 12-10-2011, 03:23 PM

A question for the engine builders out there...

I am looking at the GM Performance Parts BBC block, part # 19170538. The block is made for use with a 1 piece rear main seal crank and oil pan. I see that there are adapters to convert it for use with a 2 piece rear main seal crank. Is there a way to convert the block to use the 2 piece rear main seal crank and oil pan? Looking at the higher end bowtie blocks with 2 piece rear main seals, it looks like they use a 2 piece rear main seal main cap and some sort of aluminum adapter plate bolted to the block. I don't see any listings for the main cap or adapter plate, nor have I found anything with other manufacturers.

Any insight would be appreciated. Thanks!

Jeff Jewell

Mike Taylor 3601 · 12-10-2011, 06:06 PM

You can put adapt for 2 pc. seal like you've seen, but oil pan is different where it meets up with rear cap, but I have seen blocks that have rear cap for 2 pc. seal and block is machined for adapter that bolts to block and holds seal,it was bowtie block.
Don't know if came that way or was modified,if had to modify to that configuration would be cheaper to buy pan.
I think you could modify pan for 2 pc. to fit 1pc.by changing that section in pan.
Mike Taylor3601

12-10-2011, 03:23 PM	#1
Jeff Jewell Member Join Date: Jun 2002 Location: Bangor, PA Posts: 182 Likes: 41 Liked 171 Times in 36 Posts	GM Performance Parts BBC Block Question A question for the engine builders out there... I am looking at the GM Performance Parts BBC block, part # 19170538. The block is made for use with a 1 piece rear main seal crank and oil pan. I see that there are adapters to convert it for use with a 2 piece rear main seal crank. Is there a way to convert the block to use the 2 piece rear main seal crank and oil pan? Looking at the higher end bowtie blocks with 2 piece rear main seals, it looks like they use a 2 piece rear main seal main cap and some sort of aluminum adapter plate bolted to the block. I don't see any listings for the main cap or adapter plate, nor have I found anything with other manufacturers. Any insight would be appreciated. Thanks! Jeff Jewell

12-10-2011, 06:06 PM	#2
Mike Taylor 3601 VIP Member Join Date: Oct 2008 Location: Somerset,Ky Posts: 1,362 Likes: 336 Liked 279 Times in 96 Posts	Re: GM Performance Parts BBC Block Question You can put adapt for 2 pc. seal like you've seen, but oil pan is different where it meets up with rear cap, but I have seen blocks that have rear cap for 2 pc. seal and block is machined for adapter that bolts to block and holds seal,it was bowtie block. Don't know if came that way or was modified,if had to modify to that configuration would be cheaper to buy pan. I think you could modify pan for 2 pc. to fit 1pc.by changing that section in pan. Mike Taylor3601