GM Performance Parts BBC Blocks

A while back there was a discussion of aftermarket BBC blocks. I'm curious to know if anyone has first hand experience with either the GM Performance Parts BowTie BBC or the BowTie Sportsman BBC blocks. Potentially being in the market for a 4.5" bore block, I thought I'd see what people thought about this option.
For my use I'd be leaning towards the BowTie rather than the Sportsman since the BowTie accepts Mk IV cranks, oil pans and timing covers. Sportsman is a little cheaper but that difference would be more than eaten up with the cost of a new oil pan.
Anyone else have any thoughts or experiences?

I think it was wannabe and fcpilot, that had concluded my own feelings. They are all great blocks once you go through everything three times. My opinion for the budget minded would be to find a used one from a reputable engine builder that has already run the machining gammot once or twice. Or plan on going through it completely yourself. I have personaly had to index and bush the lifter bores on a new GM bowtie. Other than that and the hand grinding to get a double roller chain to fit (gen 6 bowtie) It was a pretty nice piece! Check the line bore, cam bore, deck parallel and squarness. These were areas that have also needed attention on bowties in the past, for me.

Yep, I have been very happy with them. I think there are four of them in our shop right now. I can't even count how many passes we have on one particular one in our funnycar. If it is not over a thousand it is darn close. After checking it out after the last tear down we found nothing wrong so it is in the process of going back together again. I like MachineHeads thinking about finding a used one in good condition. It can save you a bunch of head-aches with some of the details that you have to address on any new block.
Paul

Check with "NUTHIN" here on the boards. He has has a few "Groose" motors and they were GM performance blocks. I think one of them were Aluminum too.....

Thanks for the info. Pretty much figured any block would need a thorough checking and finish machining before use. Mostly I wanted to be sure there were no inherent deficiencies in the GM stuff.
I, too, like the idea of a "used" block, and have been keeping my eyes open for one. Unfortunately those I have come across(GMPP, Dart, Merlin) have fallen more into the "used up" category and in need of repair or already bored out to the limit. I'd rather spend the $$$ on prepping a new block than rehabbing a damaged one.
Check with "NUTHIN" here on the boards. He has has a few "Groose" motors and they were GM performance blocks. I think one of them were Aluminum too.....
Mike, I do believe you mean "Grose" as in Ron and/or Joey Grose. They're up here in my area, as well.

Hey Craig, I have a Gen IV block I'll be gettin rid of. Has 2 cracks from head stud to water jacket. Is this too damaged for you?
I'm going with a Dart block.
Jerry

Hey Craig, I have a Gen IV block I'll be gettin rid of. Has 2 cracks from head stud to water jacket. Is this too damaged for you?
I'm going with a Dart block.
Jerry
How many tubes of JB Weld do you figure it'll need? :D
Sounds like a good candidate for a "mock up" block, though. I'll haul it away for you.
Maybe we can get a package deal on the Darts?

Ive had better luck with a propane torch and tile grout!