I've read and read until I see crossed eyed. I know in a car application a studded 2 bolt block can handle close to 1000 hp but these are short bursts down the track, not going 5000 rpm or more for extended lengths of time like in a boat. I'm having a hard time finding some 4 bolt 454 or 427 blocks. I'm sure they're around but people don't want to give them up. I was thinking about a studded 2 bolt block with main cap girdles. Any thoughts, experiences or suggestions would be greatly appreciated!!

In the late 80's Mercury 454 ci 330 HP used a 2-bolt main. The 454 ci 370 HP and 420 HP were 4-bolt. Obviously, Mercury didn't think the 2-bolt was worth the risk. How much will you save with an upgraded 2-bolt vs. a stock 4-bolt? In the scope of the whole project, is it worth the risk?
Ben

I'd much rather have a 4 bolt block, but it's a seemingly hard item to locate. Like I stated, I'm sure people have them, but I feel they are saving them for a rainy day.

Might all work out might not, is it cost savings worth the risk?

https://s.yimg.com/fz/api/res/1.2/tV...5f_gallery.JPG

I picked up a gen vi out of a 97 dump truck. It was a 4 bolt. N not sure if you want to change to the gen vi or not

I'm leaning toward a gen IV because I have intakes and some other parts available to me. But if I should stumble onto some newer blocks I wouldn't pass up a good deal.

I have a gen 5 .030 over for $200 clean it and it's ready for assembly. Intake mkiv, gen 5 gen 6 all the same

Don't I need different heads for a newer block though?

I believe you do but only for the gen v. The gen vi they went back to being able to use the same heads.
Again I'm no expert but that's what I read

I'll have to do some more research. Thanks for all the input.