7.3 vs 6.4 vs 6.7 Cummins

[oceanstateperf]

Trying to decide between 3 different trucks based on engine & drivetrain.

'02 F550 with a 7.3 and auto trans
'05 F450 with a 6.7L Cummins conversion (out of an '08 3500) and the Ford ZF 6 speed manual trans
'09 F450 with a 6.4L and auto trans

All are loaded Lariat crew cab 4x4's pickups . This would be my daily driver and also be used to tow around 20k lbs. Not looking to hot rod it to death but would like to get around 400 RWHP / 800 - 900 ft lbs. Looking for the best combination of long term reliability, durability, power, and fuel mileage. What do you think?

Thanks, Pat

[tsteel]

The 6.4 would be the easy way to get the power you want by getting a spartain tune exhaust and cold air intake.

[ianstew]

Originally Posted by tsteel

The 6.4 would be the easy way to get the power you want by getting a spartain tune exhaust and cold air intake.

yep..........6.4 will be easier to get the power

but i'd go with the 550 cuz its a 7.3......just my personal preference

[jethro]

go 7.3 take some of the money you would have spent on the 6.4 and mod the 7.3 some just my .02

[tsteel]

Originally Posted by ianstew

yep..........6.4 will be easier to get the power

but i'd go with the 550 cuz its a 7.3......just my personal preference

I love my 7.3 and have had 7-8 of them but I was just suggesting the 6.4 for durability and dependability after the mods.

Originally Posted by jethro

go 7.3 take some of the money you would have spent on the 6.4 and mod the 7.3 some just my .02

By the time he gets the 7.3 to make the pwer he wants he will be at a 6.4 used price tag.

7.3 will need a TW chip, Injectors, Exhaust, Cold Air Intake, gauges, possibly a HPOP upgrade, AND LAST A BUILT TRANS to hold the power and the heavy towing. So after the mods and built trans he would have $10,000 or more in just the upgrades to get the power. Then comes the factor of the dependability. One example is MattP's OBS was modded alot and only made 500 RWHP give or take but the truck had issue after issue.

The 6.4 seems to be doing best with the HP department and dependability after being modded.

[shu873]

Depending on who did the 6.7L conversion and how well of a job they did I'd be all over that one... DPF delete and a mild tune will put you where you want to be.

[dieselmac99]

depending on build quality and your abilities with a standard, I'd say jump in the conversion. However, if you're cool with ditching the DPF, I'd say the 6.4 is the runner up. Even if it is an auto....