My
:
There are at least 3 different carbs for the five ton. There is the Zenith (cast iron), and two versions of the Holley (one aluminum and one cast iron) The cast iron versions are roughly 25 lbs each. Yikes!! I have all three and can try to answer any specific questions if you have any.
Just for reference: Saturn Surplus has the Zenith for $125.
Look on this page:
http://www.saturnsurplus.com/m35/m35-2.htm
It is NOS. Here is the pic from their website:
http://saturnsurplus.com/m35/5tcarb.jpg
I have installed the Zenith. It does bolt directly to the intake manifold - same as the Holley - six studs. Be careful those intakes are brittle!! - and the attachment to the air cleaner is the same.
However, the lines for the governor, fuel line, and accelerator rod are in different places, . . . the necessary fittings to adapt are included with the Saturn kit, but I don't believe any of it is too difficult to fabricate or find at the hardware store.
Please note: it appears that you no longer can use the engine stop cable with the zenith. The zenith has no degasser valve or no provisions to hook it up? I guess you just have to kill the spark with the ignition switch or pull out the choke to shut it down?
I can't comment on the mileage differences - I haven't tried to accurately measure mine. Besides, there are so many other variables that affect the mileage, it would be unfair to say that one carb is better than the other without a comparison on the same truck (changing only the carb, and nothing else)
As I said before, let me know if you need any specific pictures or dimensions.