Well it is a four bolt main block anyway (they all are from the one piece rear main seal GEN V and up). Is this a Mark IV block with a two piece rear main seal? Or do you have a Gen VI block with a one piece rear main seal (the Gen V BBC 454 had no provision for a mechanical fuel pump as it was used only in EFI vehicles).
This is a Gen VI 8.0L 489ci block bored .020 to 494ci. I'm trying to keep it relatively stock looking, so no turbos or blowers.
I'd get the money back.
Just would never be comfortable going forward.
Looking at the pictures, I think I see the "spider" that holds down the dogbones for the stock roller lifters, so judging by that, it's a Gen VI, and therefore also a 4-bolt main and a one-piece rear main. It also has the mechanical fuel pump boss, which means it is a 454 block. If it does in fact have the 4.25" stroke, then you have either a 489 (.030 overbore) or a 496 (.060 overbore). Probably why they were calling it a "502", although the latter has the stock 4-inch stroke and a 4.5" bore. That being said, you can make plenty of power with a 489 or 496, if you put some decent heads and a healthy cam in it. You could probably find a GM ZZ502 cam as a takeout, and add a set of the AFR 265 oval heads and have a real stump puller. Even with the flat tops, the AFR's are available with 110 cc chambers, which should yield a pump-friendly 9.6:1 CR, or thereabouts.
Depending on how they want to work with you, you still might have the makings of a good street motor. What are the casting numbers on the heads?
Gen VI 489ci 8.0L block. The heads are nothing special stock 489 heads with 2.09/1.72 valves.
Also, there are double roller timing chain sets available that will clear the stock aluminum 6-bolt timing covers. I used one on the 489 that I built for my boat.
This motor was all together when I got it, so the timing chain fits under the stock cover.
So basically you have a short block that needs pistons. If he will give you a set of alluminum heads, then buy some pistons to get you where you want to be, should be at least 10:1 with the alluminum heads.
With the new slugs, you are now into it for $3,000. Check out what blueprint is at on a 496 short block for comparison
After doing some thinking, these are my thoughts as well. A Blueprint 496ci is $8,095 through Summit. Just the short block is $3,695.
My friend is the middle man and I decided to give him a chance to make it right. I have no interest in talking to the builder because the ending of this would be very different... My friend has set it up so I'll be receiving a set of aluminum heads and the new cam I want.
I might put new pistons in and I might not. I want to take some measurements first and see where I am. If I'm over 9:1, I'll leave them for now. I just don't want to spend anymore money right now....
Thanks a lot for all the comments guys. I appreciate the feedback.