Which cam for my 4.8?
03-28-2016, 09:49 AM
#1
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Which cam for my 4.8?
Ok, I'm getting ready to replace the cracked Castech 706 heads on my 2000 GMC Sierra 4.8 with a set of reconditioned non-Castech 862 castings running Chevrolet Performance 12499224 springs. While doing so I'm going to change the cam/lifter and probably timing chain. I'm looking to run either the Comp Cams XR259HR or XR265HR cam. My question is I've been told I should shave a little off the heads for starters. How much?? Also which cam would you recommend for good performance but will pull my 18' bass boat often? Initially I will be running the stock exhaust manifolds but plan on putting long tubes and a full mandrel bent dual exhaust on it not long after. I also will be running the stock converter initially but an not against going to a slight higher stall if it's recommended. The trans I had rebuilt a few years ago and it currently has a corvette servo in it so it's got a real snappy 1-2 shift. It also has a 3.73 gear with an Auburn limited slip unit. Stock size 15" tires.
Is a new oil pump recommended or will my stock one be fine? I was told I should replace the pickup O-ring though. TIA
Is a new oil pump recommended or will my stock one be fine? I was told I should replace the pickup O-ring though. TIA
03-29-2016, 07:45 AM
#2
https://www.performancetrucks.net/fo...-heads-434041/
There's a little math formula in this thread that can help with your milling question.
As for the cam..
I would be very careful with taking other peoples advice on cam selection. I have always paid for my cam advice, and this method has treated me well.
I have always used Ed Curtis with FlowTechInduction to design a custom cam for the engines I build. They've performed exactly as I wanted them to.
There are plenty of sponsors here that would be glad to actually listen to your goals and either design a cam for you, or know which of their shelf cams would suite those goals best. I'd spend a few bucks extra and get with one of them.
There's a little math formula in this thread that can help with your milling question.
As for the cam..
I would be very careful with taking other peoples advice on cam selection. I have always paid for my cam advice, and this method has treated me well.
I have always used Ed Curtis with FlowTechInduction to design a custom cam for the engines I build. They've performed exactly as I wanted them to.
There are plenty of sponsors here that would be glad to actually listen to your goals and either design a cam for you, or know which of their shelf cams would suite those goals best. I'd spend a few bucks extra and get with one of them.
03-29-2016, 09:08 AM
#3
in a 4.8 its tough to slap in a cam thats goign to do any better off the bottom than the stock cam. If pulling the boat is priority 1 im not sure I would be looking at cam swaps first. Boost will get the job done better.
If youre dead set on a cam those comp cams will be OK, but the smaller motor will want a tighter LSA to help boost low-mid torque.
If youre dead set on a cam those comp cams will be OK, but the smaller motor will want a tighter LSA to help boost low-mid torque.
03-30-2016, 11:53 AM
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in a 4.8 its tough to slap in a cam thats goign to do any better off the bottom than the stock cam. If pulling the boat is priority 1 im not sure I would be looking at cam swaps first. Boost will get the job done better.
If youre dead set on a cam those comp cams will be OK, but the smaller motor will want a tighter LSA to help boost low-mid torque.
If youre dead set on a cam those comp cams will be OK, but the smaller motor will want a tighter LSA to help boost low-mid torque.
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