1989GMCJimmy

I am going to be a full restomod on a full size 89 Jimmy. I own a shop and we had to install a used engine on a Vortec Max truck, and when I found out the engine was an all aluminum L76 core I didn't send it back. Bought the GMC and viola, a home for the L76.

Truck has 35's 4.56 gears and will have a 4L60E. Seems I won't be making the most of those rectangle port heads in this truck application, but whatever. I was told by Justin at Blackbear who is a friend of mine that he likes the Comp 54-412-11 XR265HR Specs are as follows
RPM range 1200-6000
Intake at .050 212
Exhaust at .050 218
Intake lift 0.522
Exhaust lift 0.529
LSA 114.

I want good sturdy midrange as this is a truck, and it will be used to tow from time to time. Thanks for the assist.

G Atsma

That will be a great cam for your truck! With -13 overlap it will run smooth and still have great low end and midrange.

1989GMCJimmy

What kind of horsepower and torque would I see with long tubes and a tune with this?

1989GMCJimmy

I have a BTR Stage 2 NSR cam that I was going to use for this engine when it came in the shop. Since it sounds like this Comp unit is worth buying do I need to move off of the LS6 valve springs I had the machine shop install that were originally for the BTR cam and use comp 918's instead?

G Atsma

The LS6 springs will be fine, with enough lift capacity.