Hello all I was looking at texas speed website, and was wondering what the differnce was between the 402 and the 408 beside displacement and iron vs alluminum, and the short block vs long block.

Im looking to go NA, but it would be nice maybe way later down the road to boost it, but who knows.

Anyways I would like to palce an order for one of these fine engines, as well as a patriot stage III head, and an ls6 intake manifold.

Any other suggetions for my buildup?

Stock everything so far.............
98 ws6

 

The difference is bore size, 4.030 Vs 4.060 (alum>iron), stoke is the same at 4.00

Fast 90/90, headers (preferably 1 7/8 or stepped, clutch and differential (stock won't hold long with that kind of power), of course tuning.

 

The advantage that I see would be that a 408 will allow you to use a LS7 Head. What is the weight savings with the LS2 block over the LQ4? That would be one that I would have to measure. I know it is like 70lb between the factory 5.7 and the LQ4.

 

The advantage that I see would be that a 408 will allow you to use a LS7 Head. What is the weight savings with the LS2 block over the LQ4? That would be one that I would have to measure. I know it is like 70lb between the factory 5.7 and the LQ4.

 

actually 92lbs

 

You need a minimum of a 4.1 bore to run an LS7 head unless you run the ETP 4inch bore LS7 head. In that case you could run them on either one.

 

402=4.000 bore
408=4.030 bore
414=4.060 bore

 

I went with a 408 iron recently and Im planning to spray it in the near future. Also, you will probaly have to decide how soon you will do the turbo or stay NA, just because of the compression. Unless you just want to stay down a few HP's for a while.

 

Yeah, 400 is the stock 6.0L bore for both iron and aluminum blocks, which with a 4" cranks would come out to 402. Iron blocks are routinely bored .030 over to make a 408. With sonic testing you can take them to .4.060 if all checks out. The new L92 block will be a 4.065 IIRC.