Theoretical transmission upgrade P-30 454
I have a 1989 Mallard Sprinter with the Chevy P-30 set-up. 454 engine, etc. Runs like a champ and I love it. If I really got a wild hair and wanted to replace the transmission with an overdrive tra...
Forum Discussion
User,
I suggest that you very seriously consider your options.
If this is a plan to get better fuel rate, you may just not get there. Even if you get an extra 1.0 mpg out of it, the payback will be forever. The problem is that the chassis was sold for that service with a best guess final drive ratio. That will put the engine near its torque peak at cruise. If you back down from there, you will be running higher cylinder pressures (more ring wear) for the same speed.
If, on the other hand, this is a hobby move, I suggest you find a recent wreck of a C or G3500 with 8.1 liter. Buy the whole thing and then pull out the driveline (Do Not Cut anything) with all its associated controls sensors and of course the ECU and body controller (may be needed for other things. and then scrap the steel.
Good Luck and keep dreaming, sometimes thing work out.
Matt
I suggest that you very seriously consider your options.
If this is a plan to get better fuel rate, you may just not get there. Even if you get an extra 1.0 mpg out of it, the payback will be forever. The problem is that the chassis was sold for that service with a best guess final drive ratio. That will put the engine near its torque peak at cruise. If you back down from there, you will be running higher cylinder pressures (more ring wear) for the same speed.
If, on the other hand, this is a hobby move, I suggest you find a recent wreck of a C or G3500 with 8.1 liter. Buy the whole thing and then pull out the driveline (Do Not Cut anything) with all its associated controls sensors and of course the ECU and body controller (may be needed for other things. and then scrap the steel.
Good Luck and keep dreaming, sometimes thing work out.
Matt
