LH6, LL4 ?????????

[Flat57]

I'm looking through a GM wiring diagram for 88 trucks, (I don't have one for my 85, but the 88 is supposed to be quite close). The diagrams show differences between LH6 and LL4 engines. Will someone tell me what the key differences are between LH6 and LL4, and also, what do I have in my 1985 C10 suburban? I do know that I have EGR (right on top of the intake manifold inside the air cleaner, right), and it is a dual plane manifold.

Thanks,

John.

[smcghan]

As far as the wiring diagram, I don't know. The engine is a "C" which is the lowest performance version. But can be modified (intake change etc.) I hope this helped a little.

Steven

[86burb]

VIN "C" = LH6 light duty emissions (with EGR)
130hp @ 3600rpm, 240lb-ft @ 2000rpm
GVWR under 8500lb
VIN "J" = LL4 heavy duty emissions (no EGR)
148hp @ 3600rpm, 246lb-ft @ 2000rpm
GVWR over 8500lb
These numbers are from the 1986 GM factory dyno tests. The LL4 shows a flatter torque curve than the LH6.
-LL4 shows 220lb-ft @ 1200rpm rising to 246lb-ft @ 2000rpm with a gradual decrease to 220lb-ft @ 3600rpm ,this is for the C,K,P models, the G model shows 230lb-ft @ 1200rpm rising to 248ft-lb @ 2000rpm with a gradual decrease to 230ft-lb @ 3100rpm and then dropping to 210ft-lb @ 3600rpm.

-LH6 shows 220ft-lb @ 1200rpm rising to 240ft-lb @ 2000rpm staying flat to 2400rpm then dropping to 220ft-lb @ 3000rpm then to 190ft-lb @ 3600rpm.

The ratings are corrected to 29.32"hg and 77'f dry air with the engine in the vehicle.

Hope some of this info is usefull.

[Flat57]

Thanks for the information. I've purchased a single plane intake manifold and an ATS turbo that I'm going to put on that I hope will make it a little better.

[DmaxMaverick]

Need a wiring diagram for 1985??

Click on the link in my sig. for some high res. scans. Be sure to view them in full size for good detail.