Ok...I just about had my mind made up on buying an LQ4 6.0 for my truck. I fiqured the lower compression would be moore boost friendly for the Whipple. I just noticed though that the LQ4 makes peak hp at 4400 rpm's, the LQ9 peaks at like 5200.What route do I need to go? I'm running 4.10 gears and a 3000 stall so It needs to be able to pull more than 4400 rpm's.
Who all is running a LQ4 with stock internals?? Is that what Parish was running?and wasnt he shifting gears at 5800?? I'd hate to get an LQ4 if its going to fall on its face after 44-4500 rpm's.

 

The LQ9 also has 10.0:1 comression also. Just because something makes peak power at a certain RPM doesn't mean it can't be reved up more.

I don't see that LQ4 falling on its face at 4500rpms...hell my '88 F-150 with its 9.0:1 compression, junk E7 heads, 5.0, and 187/193 cam pulls to 5000rpms before falling flat.

If you are still concerned about it falling short, a stock LS1 F-bod cam is a bit larger than the LQ4 cam I think or a used Z06 cam advanced 4* would work well and be cheap.

 

Go Lq4 if your going to run Boost the lower Compression will be better for that whipple and it's Hot air Charge
The whipple will take Care of any Falling on it's Face Problems
You should Consider a Small Cam while you have the engine out of the truck
A nice Small Blower Freindly Cam Comp 212 218 would be nice I'm sure

 

Looks like I'll be going with an LQ4 then. Now, if I just had an idea what a new one cost??
Anyone know if these are available in a short block? That would help out with cost.
LQ4 part number anyone???

 

i was running the lq4, very boost friendly.

you want the entire motor, the heads are part of whats good about a 6.0. seems like a new crate motor is around 3k, you could go that route or you would wait till a ready to run used one comes along for 1200-1600 or so.

there is one other option especialy if you plan on pushing it later on down the road, buy one of these knocking take out motors for something like $800 and rebuild it with forged pistions, small cam and rod bolts. you would end up with a few more cubes and i think be right around the price of a new crate motor.

 

the LQ4 doesn't fall on it's face at 4500....hell, mine pulls hard to 5600 (rev limiter) and that's with the stock cam...the toque peak is at 4000 and the HP peak is at 4400 but it still pulls hard after that

 

thats right, infact when i sprayed mine it stalled right up to 4700 and i dont think it ever went below that rpm. my stock shifts were at 5200(i think) i bumped them up till i was at 6200, it kept geting quicker up to 5800 and then at 6200 started to drop off a little. i set them at 5800 from then on.