bradenW

Iron blocks don't come with 6-bolt deck for heads unless you get the LSx block, and it's a heavy sucker that requires a ton of machining.

Also, if you want a light alum 4-bolt block that will hold a lot of power, the alum 5.3s from 05+ I think, are proven tough as hell. 800+ no prob.

ysb02

Unless you want to road race the car (with 1k hp probably not) go with iron. No point in spending the extra cash to go Al and have it bite you later on.

Corvette-Chris

I wouldn't be afraid of an alum. block that was re-sleeved from Steve @ R.E.D. (or ERL for that matter).

bradenW

Depends on how competitive you are. 100 lbs can make a difference. For the record, I do have a 4 bolt headed iron 408 in my C5 that I don't plan to push much past 20psi. Outlaw car and C6 Z0 have erl superdecks.

Slow Z06

No road racing, no drag racing anymore. might just do the 402 Iron. I have no issue running 4 bolt heads at 23psi right now. The larger cubes "should" produce the power sooner with less boost as compared to the 347 I have now.

Thanks for all the input

0ERL PERFORMANCE

Our sleeved ERL blocks are as reliable if not more that the iron blocks. We don't have issues with the sleeves and since our sleeves are made of ductile iron, the cylinders are 3 times stronger than the cast iron cylinders.

The other big benefit is that our sleeves are longer that the cast iron as well. This helps because most people are putting in at least a 4.000 stroke crank and sometimes bigger and with a cast iron block the cylinder length is much shorter which means more of the piston is going to come out of the bottom of the cylinder and have a chance of rocking and or lots of side load.

Our longer ductile iron sleeves helps in keeping the piston up inside the cylinder which helps oil consumption due to blow by from excessive skirt wear.

Mike04

Another option is the RHS block, expensive but nice.

5 Liter Eater

I'm biased but I like the iron block route for strength as well as wallet thickness. Whether or not you stroke it or leave it at a 370 is debatable. I personally don't think my cubes are helping that much given my small turbos (57/62's). I do like the iron block though. It gives me more of a warm fuzzy than a stroked LS2/3 would. Just missing the extra head bolts.

5 Liter Eater

I thought you already did this though Jerry? Wha happen' to yer motor?

slow ride

A 390 iron is nice also for cheap. Little more meat left in the piston and keeps the piston in the block more at BDC. Use good heads and 1/2" headstuds or stock size 2000 or l19's for a solid 4 bolt setup. Head/block surface is important also. I hand lap/hone everything I put together.

robert miller

Mike, I am running CCW sp500 13 inch,s wide. Robert

Slow Z06

I got some blow by pushing out my filters in boost. Figure since I need to go into a motor, I may as well go bigger.

99FRC Newb

Because they are heavy and throw off the weight distribution.

slow ride

It's like 80 lbs more for a standard iron block. Just think of the weight you add with the supercharger/turbocharger components though.

Corvette-Chris

I believe that is the issue most of the time. 80-100 lbs for the iron block is a lot when we all already have a lot of extra weight added by TT/SC setups, roll bars, etc. One of the big issues of why I went back with an LS2 block was the fact that it runs cooler and I am still using a stock radiator and fans without issue.