They both are availible w 1 piece rear main seal. Both can be bored, but the zz 502 only once for the most part. Are they interchangable in the applications, or will one just not work in another application. It just seems like it would be better to spend an extra 500 for a bow tie block.. Thoughts?

the bow tie blocks are nice but i like the dart big m block better.

I'm building a trolling motor compared to your deal SO I wont be useing the more expensive Bowtie block w the 2 piece rear seal. But they do make a bowtie the same price as the zz 502. Why woouldn't I go for the bowtie w the better main caps? Only thing I can figure is all my stuff wont bolt right on it. But who knows

I actually just ordered the newer Gen 6 Bowtie block from Summit. They had free shipping and it came to about $1890. The standard 502 block isn't much cheaper at all so why not go to the bowtie? At least those can be bored to 4.600 and have stronger webbing and splayed mains. No brainer choice.

http://www.summitracing.com/parts/na...Faxr7Aod12IAag

the bowtie blocks much better deal....

I'd spend the extra $500 and go with Dart big m. The motor is only as good as the foundation, build it right the first time. It's always cheaper in the end.

Thanks for the replies. If i was building a funny car i would go w aftermarket. I just want the gm block . I think gm makes good stuff. I heard some things are dif. I just want to do it right. Ill probably go with a block with 6 bolt timing cover. I am real picky. I want factory stuff not aftermarket. Not fudged. Maybe the bowtie block is just a gm version of afternarket. Probably be best if i could find a 10 year old 300 block.Thats why i asked about the 2 gm blocks. Once again. Thanks for your input

The factory blocks are good enough for mild power I think. The bowtie is a Gm race block. I'm not sure but I think up to gen8 block they are all the same mounting holes?? I'm not completely up on all the diff big block stuff tho!!

Same here....still trying to figure out which ''early parts''will fit my gen7.

Yea. Why are both blocks the same cost. Yet onevis machined really nice w nodular iron caps. I know one gas 10 bolt cover and one has 6 (timing cover) i guess noone has the balls to share their experience .(that has been here). But you have a zz502 block it cracks .. why even thonk about another zz502 if a bowtie block cost the same ? Truly baffeling. The only one that costs more is a truck block.