Dave Ohgee

I currently have a set of cathedral port SPS street fighter heads. They have 2.055/1.600 valves and about a 235cc port. Looking to get a new short block but my question is what route should i go. Would it be worth getting a 408 or just run say a 370. This is a “street” car but primarily drag races. I do drive it to work and do pre race 40-50 mile cruises. Nitrous car also.

99 Black Bird T/A

iTrader: (4)

408 would be my choice

R6cowboy

iTrader: (3)

3.90" stroke 398...?

Tuskyz28

Rather have a 402 ci LS2 over a 408 ci LQ iron block.

You will feel the 100 pounds difference vs 6 cubic inches...

99 Black Bird T/A

iTrader: (4)

Excellent point! Agreed 100 less on the front is always good.

I would be tempted to roll the dice and punch the LS2 block .030 over for 408 and hundred pounds less. That's what I eventually hope to do with my LS2 block.

R6cowboy

iTrader: (3)

Isn't max overbore for the LS2 0.030"? All iron 6.0 blocks have 0.060" max overbore.

99 Black Bird T/A

iTrader: (4)

By the book .020 is max on LS2 but several folks have went .030 or a little more. I think .060 on iron is regarded as safe but I've read on Yellow Bullet some 6.0's have went .125 over for a 4.125 bore

R6cowboy

iTrader: (3)

Ok, I always thought 0.030" for LS2 and 0.060" for iron 6.0 was the "safe zone" for overbores. Some irons being able to go 0.125" is pretty sweet.

Tuskyz28

I honestly would do a 403 cubic inch max motor.

Keep some meat on the cylinder wall for the heat of the nitrous....

After all 6 cubic inches is only worth 9 to 10 horses in naturally aspirated form.