subtlez28

iTrader: (15)

I've been searching around and have had limited results. I'm hoping one of you could school me on the base circles of LS7 and LS9 cams compared to stock LS3/L92 Cams.

My situation is this: I am converting an L92 into an LS3 (intake, pan, balancer, VVT delete etc). I have two friends who slapped LS7 cams in L92s w good results (except some possible valve train noise). From my research it looks like the LS7 and similar LS9 cams have a smaller base circle.

Will the combo of an LS7 or 9 cam in an L92 require custom length push rods?

Is there a difference in LS7 vs LS9 base circle making one more desirable for my application?

Thanks in advance!!

Tainted

iTrader: (9)

You really need to measure with a pushrod length checker. I have no idea what their base circles are, but the noise can be from incorrect length pushrods. Its a $20 tool and you know you will have the right length

subtlez28

iTrader: (15)

You are correct, and I'm not going to argue w that logic.

Only problem is I do not have the parts in hand. I am in the researching stage. Seems in the LS world, everything has been done already. Usually many times over. Just hoping someone who has already been there could advise.

Gunslinger09

Did your friends mill the heads of the motors they converted? I believe the cams are all the same base circle, so absent that the stock length pushrods should work. Like Tainted mentioned before the wrong rod length is one reason for the valve train noise so get a checker when you do the actual conversion.

subtlez28

iTrader: (15)

From what I have read on here, the LS7 does have a smaller base circle. I am wondering if the LS9 is the same, and what the difference is between them and an LS3/L92 cam.

I'm assuming the difference is minimal, but the numbers have to be out there.

Both of the L92s I mentioned w LS7 cams have been running for years. The valve train noise is minor, and may not even be related. Perhaps the hydraulic lifters can make up the difference. Neither engine was opened up, so no milling. If anything, my thought was longer push rods would be needed (to make up for the smaller base circle).

AVB

iTrader: (9)

I put an LS7 cam in an L92 longblock I picked up and used stock pushrods w/ no problems. Eventually, put in hardened 7.35's and got torqued w/ less than a full turn, which is what I like.