5.3 L33's run 4.8 pistons (Part number is the same) for 9.9 to 1 compression.

 

my thoughts were that the MPG (especially when towing) won't be any worse than it already is, towing with a 6.0 I would assume would be better mileage than doing so with a 5.3... I haven't done much gas motor towing so I'm not sure.

 

How hard is it to find a 6.0 in new york?

 

can't be that hard... ofcourse thats easy to say living here where they are sitting on every street corner...

 

I haven't heard of anyone getting better than 15 mpg with a 6.0. I get 20 with my 5.3 all the time. Thats a big hit. I get over 11 towing the trailer and I haven't heard of anyone getting over 9 towing, thats also a big hit. I'm on several camping forums where this is a common topic. I can live with it with the power it makes but if I have to get into it to to freshen it up that would be a great time to enhance it.
I haven't looked for a 6.0 because of the reasons I stated but I'm sure they can be had. I bought an under 100 miles LM4 5.3 for my Corvette project on line so I have no qualms about having one shipped here if I chose to go that route.
I've built a bunch of small block chevys over the years and would like to take a crack at the Gen IIIs just for the sake of doing it. I'm a hot rodder at heart so doing things the easy way (drop in) isn't usually the first choice.
I'm curious as to the comments on the cam. Are these the voices of experience or speculation. On the pistons, the P/N is the same so they will work and 9.9/1 wouldn't hurt my build.
Bob

 

I've heard of plenty of people getting 20+ on the highway with a 6.0 swap. You are probably reading about people with a 2500hd and a 6.0 which is COMPLETELY different. TONS more weight, higher gearing, numerically higher overdrive, etc.

 

Good point. I haven't seen the numbers from anyone who did the swap. Search button here I come.
Bob

 

Yea, don't forget that there is about a 2000 pound difference between a regular cab short bed 1500 and a crew cab 2500hd. Imagine putting 2000 pounds in the bed of your truck and driving around. You are probably going to see a decrease in gas mileage