What's the mileage difference going with that cam?

 

I don't see running the extra exhaust duration (unless you plan to spin to 6500+). On the exhaust side (with long tubes) of LS1s there seems to be no problem clearing the cylinders (don't need lots of duration). Any extra (unneeded) duration gives up efficiency.

Especially with the stock (little) intake valves, I would think a reverse split would help a bit more.

If you can't get the air/fuel in, you sure don't need the exhaust duration to get it out.

 

i was actually thinking of running a reverse split myself... on these trucks with lt's ory and a decent muffler, the intake system is where the problem comes in.. you got small valves like said above stock 5.3's are 1.89i and 1.55e IIRC compared to 243's etc at about 2.00i and 1.55e, so as far as I can tell a reverse split would work pretty well as long as the valve events work out like they should. the only thing about that is there really isnt a smaller duration reverse split off the shelf that I know of, you got TR230 (230/224) TR reverse split (227/224) MTI X1 (230/227) and the Speed inc SI007 (228/222).. the only smaller one that I have seen is MTI stealth II at 224/220 and .581/.581 on 116lsa

 

You could always have one ground. Most cam companies (both mainstream such as Comp/Lunati/etc. and people like Speed/Thunder/etc) charge little-if-anything more to "custom grind".

 

hke also does custom grinds for $355 +12.5 for shipping I havent seen a better price on a custom grind.

 

i believe i paid about 320-330 shipped for a custom grind from speen inc.>

 

212 218

 

You obviously have never done a lot of engine dyno testing with cam profiles on LS motors before........

If I only have these two choices, I pick the 212/218 because it is a BETTER CHOICE

 

I believe there was a reverse split cam thread on tech, and the end result was you can accomplish the same with a traditional split or single pattern, and there's nothing special about them, maybe if your exhaust is stock as a rock and is going to be for a while. I could be wrong, it was a while ago when I read it.

 

thanks for all the input. i'm swaying to the 5.3 with the tr220, just because it is a proven setup and many, many people recommend it.