Slowprocess, how much did the engine work and engine cost you? What are your 0 to 60 times? Im leaing toward the 6L, it just seems like it would be better in the long run.

 

Here's a question, while the 6.0 makes more power than the 4.8 and common sense would tell you that it would obviously use more gas, I have heard the argument that the larger engine would need less throttle to get the same vehicle moving the same speed, thus keeping or increasing mileage, more power/lb now. Assuming the thermal efficiencies of the engines are the same (same mech work for thermal input) what would you think. I know gonzo has gotten some pretty awesome mileage with his swap.

Realize this is all assuming the same driving style, which I don't think any of us could continue with more power available under the hood.

Andrew

 

I've heard of guys getting 408's in their full size Chevy trucks actually gaining mileage over their previoius 6.0L motors, so that would support this theory of yours.

 

I picked up the 6.0L for a steal-$950 The cam was $386.99 and the springs were $143.99. I got the slightly worked heads for $250 plus my stock 6.0L heads. I paid around $300 or so for the milled heads,valve job, and cam/spring install. I have the exact numbers there at the house, so I'll check that when I get home. That's what-$2030.98. That's really close, and I'm sure of everything but the last work, but it's close. I'm putting some serious miles on this thing a week, and it seems to be holding up just fine.

 

those guys probably get the new engine in, go really easy on it for the first few 100 miles to break it in. then compare that mileage with the older engine when they were beating the **** outa it

 

i have done the 4.8 to 6.0 swap. trying to remember my exact set up. seems like i did a stall and 4l80e and stock 6.0 all at once and my miliage droped about 5mpg. i am sure i was accelerating more quickly so yeah it is hard to compare. the 4.8 was really a pooch out of the hole. the stock 6.0 with stall and cutout was gteching in the mid 13's but i never got to the track. i did go to the track after tightening the stall and puting in too big of a cam and ran low 14's. the big cam and tighter stall was a very poor combo NA.

my current set up got over 13mpg with mixed driving including several races.

 

Wow slowprocess, were did you ever find one that cheap? That hole setup isnt very expensive. Are you breaking 5 sec 0 to 60mph? This just keeps looking better.

 

I got the motor from BigTex. They are out there, just have to find them. I don't know what the 0-60mph is. I'll have to break out the gtech this week and see. I'll let you know what it says I'm at.

 

I'd go with the cammed 6 liter and boltons then a little spray or a turbo down the road, dont expect the transmission to hold up though, I'd go with a built 4l60/65e all motor and an 80e w/the turbo

 

well, something to consider here is that mwalls54 in his 5500lb silverado ss went 13.5 n/a with a cam as his only internal mod (non bolt on mod) on 20's. the quickest 4.8 i see on the list has went 12.6. i'd say in a regular cab 2wd it would have been enough power to beat or run next to that well modded 4.8. personally, i'd go for the cubes.