Hi-

I have a LQ4 crate longblock and it is slated to be the powerhouse for a classic truck project. I want it to be tame enough to be a daily driver, but still have *****! I have been looking and reading and this is what I've come up with so far (please tell me if there is something that can be made better or more efficient):

LQ4 bottom (stock)
L92 heads (stock)
LS3 intake (90mm tb and 42# injectors)
GMPP hot cam (negotiable as I have been reading on other cams too)
Long tube headers

Right now that's what I am thinking about. Any suggestions, additions or criticisms? Be running 3.73 gears also. Truck should weigh in at about 2800lbs. Plan on running M/T S/R 29 X 15 on rear. (ok that's really all I have mapped out as of now)

J

 

I would choose a different cam, something more like a 224 or maybe a 228. That is a light truck it shouldnt have any issues getting moving and both of these cams are very streetable, they maintain great driveability.
What tranny you going to run?

 

get your compression up there, a set of milled and ported 243's are going to be your best bet. It'll be a turd with 9.4:1 compression.

 

I am not sure on a trans yet, but I have a good deal on a 4L60E so I may go that route, but again... not sure. As far as the heads/compression problem, I was going with the L92's because they are just bigger heads. I thought I might go with thin cometic gasket or maybe even get them milled. I thought I might come across a set that were already milled, but nothing so far. The L92's seem to make more horsies, if I could get the compression there, so what would the + be about the 243's? I want to be able to run pump gas and I am not sure where I need to keep the compression to street it, but I thought 10:1 was pretty decent. Again, I am a noobie.

 

The L92's when milled start running into PTV clearance issues with dish pistons. The 243's already have big ports for a cathederal head and will automatically get you to 10.5:1 on a stock lq4 bottom end. I would go no less than 10,5:1 and no more than 11:1 for a street combo.

 

how mych would you mill the 243 heads

 

there's a few write ups on the GM high Tech, Car Craft, and super Chevy. Fly cutting the pistons is not needed unless you're going to run a big duration cam.

http://www.superchevy.com/technical/...dup/index.html

http://www.carcraft.com/projectbuild...ock/index.html

 

if I go with 243s what range should I look for in a cam for something with muscle car idle and good performance while still maintaining streetability?

 

you can use the 212/218 with no stall, and the power is everywhere.
just about any cam with a -112 or lower duration will have the choppy idle. There are bigger cams than these, but you did say that you wanted something with "streetability."

You can go as big as you want, it's all in the tune . . .


here's some cam vids . . .
most of these trucks have long tubes installed with no cats.
If you want to leave the cats on, the exhaust will be a little more quiet.

all of these trucks have 4.8/5.3s in them, one or two of these vids have flowmasters or just open cutouts . . . in order from smallest to biggest

#1 212/218 .522/.529 114


same cam, but with flow masters, and LTs
http://s24.photobucket.com/albums/c3...t=100_1008.flv

#2 TR220


#3 Comp 222/224 .566 .568 -112
long tubes, open header
http://www.youtube.com/watch?v=Jb9WtZstIVk

#4 LS1 hot cam 219/228 .525"/.525" -112
http://www.youtube.com/watch?v=6oIXqyteojE

#5 TR224
http://s18.photobucket.com/albums/b1...rent=Movie.flv

#6 TSP 228/228 .588 .588 112lsa
http://smg.photobucket.com/albums/v2...t=MVI_0248.flv

 

Ok, going with the l92s. According to what I've found they'll raise compression to 10:1 and that is about what I'm after. Still considering the hot cam and I think this can price to be a great powerhouse! Kinds like the superchevy lq4 build only fuel injection. Those of you who read that article, do you think this build will have comparable results with efi? Anything I should alter/add?