Hey all. I was on Jegs' website and found what i believe to be a good matching springs for my cam. Is there anyone else on here running these? It's going on a set of 083 heads. Truly, I'm looking for a way around having the spring seats machined. (Straight spring swap)

Here are the specs:

CAM:
Xtreme Energy XR270HR Hydraulic Roller Camshaft Only
Lift: .495''/.502''
Duration: 270°/276°
RPM Range: 1600-5400

249-08-422-8
High performance application, largest cam with stock converter, noticeable idle.
Operating Range: 1600-5400 RPM
Duration Advertised: 270° Intake / 276° Exhaust
Duration @ .050'' Lift: 218° Intake / 224° Exhaust
Valve Lift w/1.5 Rockers: .495'' Intake / .502'' Exhaust
Lobe Separation Angle: 110°

The valve springs in question:

Valve Spring Kit
• 1996 LT4 Corvette Engines
809-12495494
Not recommended for cam lift over .525''.

All and any info welcome.

 

Can anyone point me in the right direction? I read somewhere in this section about using a spring set compairable to this cam without needing work on the head. Anyone?

 

I just went through the same dilemna on mine. I'm running the Comp XE269HR and the 083 heads. I also didn't want to have the spring seats machined larger. I'd avoid any of the GM springs to be honest. I've heard too many stories about them breaking and just being sub-par. You'd be much better off with aftermarket springs. Comp recommends their 986-16 springs for my cam, which require enlarging the spring seat. I found a set of stock diameter springs that have almost identical specs as the 986's. Get the Isky 235D springs and their 707-ST, or 707-STA retainers. They have 130 lbs. at the seat, and 350 lbs. per inch spring rate at 1.75" installed height. These are far superior to the LT4 springs. They cost quite a bit more, but it was worth it to me. I didn't want to risk dropping a valve and possibly destroying the whole motor by using cheap springs. Plus you save a little cash by not having to machine the seats larger. I had the orange ZZ4 springs on there before. You shoulda seen the relief on my machinist's face when I asked him to replace them with the Isky springs, and the ZZ4 springs are actually even a little stronger than the LT4 springs. They were supposed to have 110 lbs. at the seat, and my machinist said they only measured out at a measly 90 lbs. Oh yeah, I almost forgot, I also had the positive type valve seals installed on both the intake and exhaust valves. With this setup, my machinist said I'm good all the way up to .550 lift.

 

Thanks Pat! That is exactly what I needed. .550 lift you say? Are you running this currenty?

 

Sorry for the long delay in replying back! I just got my computer up and running again. I haven't got my setup running yet. The motor is still sitting on the stand at the moment. It's all assembled and ready to go, just haven't dropped it in yet.