Looking for a 4-bolt LT1 or LT4 block

[Catmaigne]

I'm gonna give this a final bump. Looks like I'll be pulling another junkyard 2 bolt to convert.

[jeffp1167]

I have a friend who did a boosted L98. Started with a clean 89 block, had it splayed, forged caps (I think) carrillo rods, 30 over, and used a zz383 cola crank (stock block was clearanced crank) Then put a pb600 on it and ran it at like 9psi. I think he used AFR 215 heads.

Anyways car was a monster (90 corvette with a six speed)

machine shop told him splayed far better then factory 4 bolt and they prefer 2 bolt blocks over factory 4 bolts for performance.

Dont waste your time on a factory 4 bolt block

[Catmaigne]

A straight 4 bolt with quality fasteners is more than enough for the amount of power I plan on making. I'd be more concerned about the block than some billet 4-bolt straight caps with ARP studs.

My biggest issue with most 4 bolt conversions is that they use caps with a pretty steep angle (like around 20*) for the outer bolts which can cut into the water jacket and webbing. However, the Howards caps are only 10* which seems much safer.

Anyway, after crunching some numbers it seems that the disparity in price between converting a 2 bolt and prepping vette block isn't that great (because it's going to need new straight caps, hardware, and a line hone probably). I guess 2 bolt conversion it is.

[noice]

Well i have a stock vette 4 bolt block that is living just fine with nitrous and methanol. You dont need a 4 bolt splayed cap for anything that is driven on the street. If your engine is detonating it doesnt matter the number of bolts in the mains. I know a guy who built sbc and would hit the traps at 10.2k on a sbc with 2 bolt mains.