After having a lobe wiped, I do not want to take any more chances. I have a 69 396, JQ, it has truck heads, not peanut port, but low comp. I believe I am running 9:1 now. I want to put a roller cam in it with the roller lifters and new push rods. Can anyone suggest a setup? It has a edlebrock performer intake and headers.
Thanks for any help.... Steve

I think a nice mild hydraulic roller would wake the combo up fine, and can be done for cheaper to last on the street. Are you dead set on a solid roller?

Matt

How bout this. There's always GM performance hydraulic rollers for sale on ebay. They're pretty mild cams, and you would just have to get retro fit roller lifters from Crane or Isky, as the GM lifters will not fit. You would need an electric fuel pump, shorter push rods, and a thrust button on the nose.

Don't even need the electric pump, you can stick with a decent mechanical. Something like 215 or 220 @ .050, mild lift, set of aftermarket lifters and correct pushrods, springs retainers and locks if you want to do it right.

Won't be wiping any more lobes.

Matt

I thought there was no mechanical pump lobe on those cams......

I don't think the new cams have fuel pump lobes, you are right. I guess we gave some (or I ) some confusing information when it was suggested to buy a late model cam off of e-bay. I was more suggesting a mild hyd. roller cam kit from an aftermarket company for a Mark IV block w/ mech pump. Lifters, cam, springs, locks, retainers, pushrods, button, and I think thats about it.
But yeah- mistake on my part.

Matt

Steve (chevyman),

Before you do anything else - find out for sure exactly what you have to work with.

I can tell you that the pistons are most likely .180 - .188 dome (18 - 19 CC). I have not seen flat tops for 396/402 motors and only the 375P/425HP rec port motors got the big dome.

If you have't done so, pull the valve covers and check the head casting numbers to validate the combustion chamber volume. Also, find out if the block was decked - if you don't know for sure, check to see if the vin number is still stamped. Also, see if you can identify what head gasket is in there.

Depending on these variables, you could have from 8.5 up to 9.5 CR. Doesn't seem like much of a difference, but in a 396 motor this is a big swing. You need know more exact before changing parts.

Just for comparison, I have a 408 motor that has been measured at 9.5/1 CR. I am going to install a XR274R solid street roller. All the hydraulic rollers I looked were either too long on seat duration and lowered my DCR to an undesireable level or very short on the seat, but offered limited .050 and lift. The low CR 396/402's can run good, but are not as forgiving as a low CR 454 motor.

MadMarv, you were correct the first time. 454HO motors have the fuel pump lobe. Even though the 502 motors don't have the boss on the block, the cam may have the lobe anyway - don't know about this for sure though.