Hello all -

I am a ex Ford BB guy who has been converted to the LS engine. You cant beat these engines for $/HP.

I hope I don't get flamed too much for these questions but I have been reading here and LS1tech and there is so much information that my head is spinning! My hope is to build a strong running engine that will make the best power and torque upto ~5700 - 5900RPM. This will be in a 4850 lb Jeep TJ (has 1 ton axles, 37 - 39 inch tires and through a 4L80E transmission.

If you could make it the way you wanted it, how would you build it? My thinking is currently as follows:

Bottom end: Leaving stock except for new pistons and bored if required. Shooting for 10.5 to 10.8 SCR

Heads: Currently has stock 317. Maybe leave stock but I have access to a set of Greg Goode ported 317 heads with 2.10 intake and 1.6 exhaust, all Titanium hardware and PAC super single bee hive valve springs for $1000. My questions about these heads specifically are will these be more heads than I for my application and is this a good price for these heads?

Intake: TBSS or NNBS and their TB

CAM: No clue here. Would depend on whether I stay with the stock heads with a port clean up or go with the Greg Goode ported variants or any other recommended set.

Fuel system: Will use Walbro 255lph in take with 3/8" lines and corvette return filter setup.

Injectors: 8.1 32lb versions

Again any guidance would be greatly appreciated.

Also vendor recommendation would also be appreciated as I want to support the forum guys for all the info they provide on these forums

 

Cam choice boils down to your goals. Are you racing or what? Your Jeep is fairly heavy, although maybe not as hefty as some of our trucks. Heavy vehicles need a lot of torque. The Brian Tooley Stage III truck cam might be worth checking out.

 

Thanks for the response Batboy. I am not looking for racing, just a healthy motor that can run the dunes and the mud. I will contact this guy about the cam. What do you think about the head and intake options? options?

 

Well, the 317 heads generally lower the compression ratio, but that also depends on what pistons you use and whether the heads are milled. Never heard of Greg Goode before, so I can't comment on how well he ports. I will say that I never heard or seen 2.10" intake valves put into those heads before. Not sure how they fit or flow. Sounds like a bigger valve than you need if you are building a torque motor.

 

Those axles, tires, trans, and weight are all going to eat your power. Just the tire height
alone will probably cost you ~75rwhp on a dyno. So torque and gearing are going to be your friends, and the hands-down easiest way to get gobs of torque with these engines is to slap a blower on it.
Just use your stock lq4, put a blower friendly cam in it, a tvs1900 & injectors, some long tube headers, (if anybody makes them for ls powered jeeps), get it tuned, and go have fun!

 

Thanks for the ideas but I cant afford $5k to put into a blower and that wont include the price of buying a forged lower end.

What is am hoping is to make the best of what I can with what I can get NA.

I have picked up a brand new NNBS with 90mm gold blade intake. I had to pass on the 317's mentioned above because they were built for a blown application and the owner doesn't know the flow numbers but Im thinking that for a NA 6.0 with a 2.08 - 2.10 intake and ported its probably too much for this application. I do have another lineup on a set of PRC 2.5 317 CNC'd heads with 2.02 intake, 70cc chambers and beehive springs. Do you guys think this along with the NNBS intake is worth having on a heavy Jeep coming in around $850 lBs or os this too much head also and I should just stick with the stock heads? I do plan to run a stall of around 2800-3000 if it helkps.

Thanks again in advance

 

I have a TJ with a 5.3 on 35s, i chose the GMT900 intake, the Ls3 camaro manifolds, K&N truck air intake, thumper 1 cam and dual 2.5" exhaust

build thread is in the projects gallery

 

Would that same combination apply to the 6.0?

 

yup, i used injectors that came with the intake, i used the stock jeep regulator as you dont need that fuel system they try to sell ya. I just tuned for the lower base pressure

 

This sounds great. So if I am hearing you right there really isn't anything to be gained from the PRC 2.5 heads for this application, I can just keep my stock heads and tune for the lower fuel pressure from the Jeep pump?