[mattybilt79]

I'm curious to know how much you tow your trailer to justify the over all loss of mpg by swapping in a big block? Don't get me wrong I'm not saying don't do it. I had an 88 v2500 burb with the tbi 350 and 400 trans that could barely get out of its own way but still could pull a trailer. It got over 13 mpg regularly. I sold it and bought a 95 burb 454 with over drive and 4.10s and it averaged 11.8 mpg! I just got rid of it due to reverse going out. Now driving an 85 crew cab dually with a 454 and just put an 87 TBI motor in it and converted it to carb. No base line on fuel mileage don't expect more than 10 out of it. Bought it to pull 5th wheel. I wanted to get away from fuel injection and electronic transmissions etc so I got an older truck. Making the TBI 454 carb'd was easy. I would rather have a cummins though but I was pinched to have my truck up and running asap. You plan on keeping your truck for awhile or updating to a newer one?