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I'm brand new to this group. I live in the Kansas City, Missouri area and have a question about cams.
My truck is a 2005 GMC Sierra 1500 SLE with a 5.3L Gen IV, TM7 motor. I've been looking at cams for the truck and found the COMP Cams Thumpr line. I keep seeing videos online of guys with trucks newer than mine but when talking to the cam companies (COMP Cams) or parts houses (JEG's, Summit, etc.) they all tell me that this cam only fits 1998 and older small block motors because of the computers.
Do the guys with these cams in newer trucks bypass the computer or is there something I'm missing. I've never done any mods like this before but I think now's as good a time as any to start.
The VIN number on my vehicle shows a 'T' for engine and that's a TM7. Whether or not it's a gen. III or IV is up in the air since the III was made up to 2005 and the IV from 2005 on. Some sites list it as a III and some as a IV.
The VIN number on my vehicle shows a 'T' for engine and that's a TM7. Whether or not it's a gen. III or IV is up in the air since the III was made up to 2005 and the IV from 2005 on. Some sites list it as a III and some as a IV.
Lots of misleading info out there.
you sir have a lm7 you do not have a gen4 motor
gen4 motors did start in 05 but not in a gmt 800 chassis
I'd admit I never looked into it, but I did assume they made a line that fits the LS motors. Was just saying that a vortec 350 cam wouldnt work in a 5.3 motor.
Comp cams has a bunch of cams for gen III/IV ls engines, both single and triple bolt!! major difference between the two gens is the cam sensor being in timing cover on gen iv instead of the back of block, dod and vvt on gen iv also, sure theres other difference, but they have an ls thumpr line go to their website and look at the cams they offer.. Or for about the same price get one spec'd out...
Last edited by Wolftrk99; Oct 2, 2015 at 11:24 PM.
The VIN number on my vehicle shows a 'T' for engine and that's a TM7. Whether or not it's a gen. III or IV is up in the air since the III was made up to 2005 and the IV from 2005 on. Some sites list it as a III and some as a IV.
Lots of misleading info out there.
You have been on the wrong sites...
Originally Posted by George C....
you sir have a lm7 you do not have a gen4 motor
gen4 motors did start in 05 but not in a gmt 800 chassis
X2 This info is correct.
All 99-07Classic GMT800 trucks with a V8 will have the Gen3 LS based engine.
Unless I'm reading this chart from GM incorrectly, if you scroll down to 2005 Light Duty Trucks, the engine code for a 'T' motor code in my VIN designates it as an LM7, 5.3L V8. Why is this wrong?
Comp cams has a bunch of cams for gen III/IV ls engines, both single and triple bolt!! major difference between the two gens is the cam sensor being in timing cover on gen iv instead of the back of block, dod and vvt on gen iv also, sure theres other difference, but they have an ls thumpr line go to their website and look at the cams they offer.. Or for about the same price get one spec'd out...
Thanks. When I spoke with a tech at COMP Cams he told me there was no Thumpr cam that would work with my computer. After talking with a lot of knowledgable friends, I found one at Summit Racing. It's the 54-600-11.
Oct 2, 2015 | 05:10 PM
Cam Question
