NEVRLIFT

My friend asked me to do some research for his '03 Corvette Z06 as he is looking into building a bigger cube motor for his car.

He is into road racing and rarely ever goes to the drag strip. One of his friends suggested he go with a 408 iron block motor as it is cheaper than the LS2 and the block is stronger. I have seen that the 408 usually makes more power but is heavier.

I feel that he should just save up for the LS2 because it seems better suited for road racing but I'm kind of unsure. Anybody know the weight difference between the iron and aluminum blocks? Which one would you choose for road racing?

Thanks.

SPD KILZ

The difference in the 2 blocks is 80lbs.

I recently had to make the same decision; and LME is now building me a iron 408. I don’t road race the car but I do drag. If I was a serious road racer I might would have put more consideration into the concern of weight distribution of the car. This is what makes corvettes superior to most sports cars on the track. For 900.00 more dollars, less cubes, and the fact that I just don’t like aluminum anymore since I had a block crack all the way down on both sides, it was a no brainier.

Now if your friend does decide to go with the iron block tell him to relocate the battery to the back. That should help to take some of that weight off.

2MuchRiceMakesMeSick

I was told buy a very good engine builder its right around 99lbs difference.
With that said I would tell your freind to get the 402 alum. block to keep the weight ballance the same because he wants to road race.
Ill be going with a 408 iron block in my car but only because I plan on putting some boost on it.

300bhp/ton

another vote for the LS2 aluminium block. Weight and weight distribution is paramount on a circuit or sprint event. Also it might be worth finding out WHERE the iron block is heavier, because raising the cars centre of gravity will be far worse than adding a little weight.

NEVRLIFT

Just an update. He ended up going with a 404ci LS2 engine worked over by MTI Racing(Atlanta) along with a Spec 3 clutch, flywheel and Callaway Honker intake.

The cam spec is somewhere in the 240/240 .600" range combined with ported LS2 heads. I don't have any good numbers on the heads, I assume that they flow pretty well maybe as good as the AFR heads.

It also has Mahle F1 pistons(11:1 compression, .01" over), CompStar rods, and a Callies crank. Hopefully it can put down some good power although I wish he had gone with the FAST intake(has LS6 manifold with ported TB).

I'm thinking that it wil be around 480rwhp. Any guesses?

EPP

iTrader: (22)

Your guess on the 480 rwhp is about what I would guess as well. It should be a strong runner. Bob

JMBLOWNWS6

iTrader: (17)

I just finished building a 402 LS2 in a 2003 vette. 526RWHP SAE corrected Hp tuners used to tune it. Made my own extensions to the cam and crank sensors. I am really impressed with the power of the LS2 with milled and ported 243's and a texas giant cam from TSP

V-seriesTech

iTrader: (5)

LS2. No comparison.

allthrottle&nobottle

Either is fine.............I have an iron block in my 97'.
Works VG at the strip, road course and autoxing.
I have spray to use one day as well so I have no issue with the extra~100lbs
Sure has not hurt its performance at all

Brian @ Texas Speed & Performance

iTrader: (1)

I would go 402. It will weigh less than the Iron Block 408 and is not really that much more pricewise and it weighs ~80-85lbs less. Give us a call if you have any questions, we'll be happy to answer any you have!

JMBLOWNWS6- The TX Giant is a good cam. We've built quite a few 402/408 motors and has worked very well! Great numbers on the motor. Let me know if you need anything else!

Brian

Cajundude

iTrader: (7)

Just put mine in over the weekend as well.

Z O SICK

iTrader: (1)

I'm looking at doing this set up in the near future. Jason, how much would this block be minus the H/C? Also, is this 402 forged?

JMBLOWNWS6

iTrader: (17)

Brian. We tuned it some more and with some juice It did 700 RWHP and 696 TQ On the 150

JMBLOWNWS6

iTrader: (17)

I think it is like 3,929

Z O SICK

iTrader: (1)

Thanks buddy.