ok I know I like automatics, that out of the way I need some info.
I have a c600 with a 330 hd. I want to know what automatic will
handle one vehicle at a time hauling... I only haul classics to shows

 

also need a set of heads... any one know where to check? I know a guy with a set of 391 heads but will they cause me issues?

 

330hd,361,391 heads are all the same on the outside, I forget if the 330's and 391's have the same bore but measure the valves at the widest part to make sure they clear.

 

You have two choices. One is a Allison 4,5 or 6 speed. I have a MT40 six speed in my 1970 C600 dump truck. Makes driving it so much better!

The second, Ford also offered the C6 in the mid 70's in the lighter spec C500/600's. Because of the high first gear/lack of adequate gears/gear spread (the 5/6 speed Allison have a nice gear spread) it was only offered with a two speed rear axle to make up for the lack of gears. The C6 in this service also seemed to fail in second gear when run for long times in that gear. Hence the trucks were set up to be in top gear (low on the rear axle though) at around 35 mph.

Hint - The MT series Allisons have lock up torque converters which the C6 does not.

FYI - I used to have a MT30 (which came stock from Ford) 6 speed Allison in my 70, but after 41 years the shifts were getting sloppy so I opted for a rebuilt MT40 which was a direct swap. Same gear ratios, just a bit heavier duty.

Also, the last of the MT30 - 40 series was 1972, so if you go a newer tranny, you will either have to look at something like a 5 speed MT650 series, or I would imagine that the lighter duty 4 speed AT540 would work, BUT having a AT540 in a Cargostar with a single speed rear axle, I definatly find a gear missing for the freeway.

How many miles at freeway speeds to plan on hauling your cars? Hills / Mountains to surmount? Grades? Stop and go or constant speeds? If you source your source your parts correctly, it is all a bolt together operation!

David

 

I had to replace the heads & Intake manifold on my C600 with a 330 when I first bought it (rusted out in the heat riser areas) I went to the machine shop that I have used for about 30 years and they had no problem doing a search and finding good castings

There is also places on line like Heavy truck Parts Net, but I have never used them nor am I recommending them, but in looking and searching they do seem to have a bunck older parts.

David

 

thanks

most helpful, I think I like the idea of the six speed, but I do have the two speed rear. I'm guessing a 4 speed will do for me. To be honest I will be going from tenn to arizona once a year and the rest is local mountains.
Thanks again!