lets rate them on flow....what would work best for forced induction, any dyno testing between the stock truck, and the others?

hooray!

 

LS6 has best flow from 3000 rpm up, average of 6+ HP over the range. Overall the stock truck manifold is very good and even flows best at lower rpms. If you go FI the LS6 one is best IMHO. I think Car Crafters or Hot Rod did a very good article on the LS1 style manifolds with all of them doing well, even compared to the LSX aftermarket. Truck manifold will not fit under the hood of the F bodies tho ( too tall ).
Oh, and you would need to change to a car water pump and use a return style fuel rail if you want to put LS1/6 manifold on the truck.

 

what about the single plane carb style manifold, converted to injection?

 

The aluminum carb style can be ported a lot more then our nylon intakes, and they out flow all but the ls6 so that helps make them more popular with the F/I guys. However, they are expensive once you figure in the work to convert them back o EFI, and aluminum retains heat, which is something that you will be battling with forced induction.

 

The aluminum carb style also seems to have some distribution problems(outside cylinders) on NA engines. On FI engines I don't think it's as much of a problem. Here are some flow numbers for each type of manifold attatched to a set of LS1 heads(I think that is correct).

LS1 Intake
.200 .300 .350 .400 .450 .500 .550 .600
141- 185- 205- 222- 232- 241- 251- 258

Truck Intake
.200 .300 .350 .400 .450 .500 .550 .600
163- 206 -224 -237 -249 -262 -265 -270

LS6/00-02 Intake
.200 .300 .350 .400 .450 .500 .550 .600
166 -211 -229 -244 -257 -269 -277 -283

 

The best for manifold for boost IMO is a custom sheetmetal intake. VERY pricey, but well worth the money for an all out FI application.

 

Anyone else notice that the truck intakes funnel down about 5 inches into the throttle opening? Also the egr block-off is sticking 3/4 of a inch into the throttle opening.
Just somethings I have noticed and will quickly fix.

 

Hmmm, good comparison X-cel. To bad you weren't selling your LS6 for about $150


btw....you wouldn't happen to know the runner length of all 3 would you? Similiar?

Kyle

 

The truck runner looks like it's a good bit longer than the LS6. The info might be on the site somewhere if you search hard enough. If not I could probably get it sometime next week.

 

I have have researched the truck intake alot. Here is what I found on a older thread:
The runners are the same length but, the runners on a truck start at the center of the intake. After the air gets pulled through the TB opening and 8 inchs to the center. I think they measured from the start of the runner instead of the actual air path.