1961 GMC 4000 with 305B

[Crosshairs6]

I bought the subject model truck with just over 64,000 miles on it. I have been watching this truck for years asking the older gentlemen if he would sell it. After 3 years I finally bought the truck. I towed it back to my house on Monday June 2nd.

He said he parked it where I found it and it was running on propane. The truck does have a standard gasoline tank behind the seat as well. I have found and ordered a GMC 1961 shop manual online but it is not here yet. I am itching to start working on my new project. Pictures of the truck are posted on the picture albums section of the site. "Crosshairs6 truck".

I want to run this truck on gasoline and remove the propane tank. What changes do I have to make to the carburetor and ignition system to make this happen? There is a toggle switch on the dash (look at pictures) but I assume there is more to this than flipping a switch. I plan to remove, inspect, and clean out the fuel tank. I want to try to get the truck started now. I will change out fuel filter and change the oil. I will change out the spark plugs and spark plug wires and probably go to an HEI ignition at some point. I just want a solid running ranch truck.


Any advice from all the experts on here regarding switching the fuel back to gasoline would be greatly appreciated. Thanks in advance.

S/F,
Shannon

[FetchMeAPepsi]

I cant help with the swapover, but I can tell you who can. Coyoterun has a truck or two that he converted to propane himself. he's the man to talk to there. (Good guy too!)

Man that's a big ol' truck! You got it for a song too. Here's a direct link for anyone else that wants to see the pictures.

http://6066gmcclub.com/forum/album.php?albumid=270

to the board! Start a build thread and I'll subscribe to it to watch you fix that monster up!

[Crosshairs6]

Pepsi,
Thanks for the information. I will send that guy a message. Yes, the truck is big. I took the seat out today along with the gas tank that was behind the seat. There is enough room to slay a rhino in the cab of this truck! I will shoot some pictures tomorrow.

As far as the restoration, I am off and running. I cut out a lot of old wiring today. I will put new spark plugs, plug wires, and run a new fuel line with inline fuel filter. I plan to send the gas tank out to a radiator shop to be stripped out and re-lined. Hopefully I will get it back before next weekend. If all goes the way I want it, I plan to have the truck running by next weekend.

Again, thanks for the information.

S/F,
Crosshairs6

[David R Leifheit]

Originally Posted by Crosshairs6

Pepsi,
Thanks for the information. I will send that guy a message. Yes, the truck is big. I took the seat out today along with the gas tank that was behind the seat. There is enough room to slay a rhino in the cab of this truck! I will shoot some pictures tomorrow.

Interesting thing to note... the Cab is the same size as a pickup cab.
All the pickup parts will work on the cab.

They are all that big inside!

[turbobill]

Those early propane kits were set up for dual fuel. The on highway truck engines recieved no modifications for dedicated propand use (higher compression/different spark timing curve/hardened valve seats).

The engine was set to run and gasoline and the propane kit allowed for switching fuels (the toggle switch turned off the gasoline to the carb and sent propane to the mixer and visa versa) along with the mixer (mounted on top of the carb), tank and hoses.

Removal of all the propane kit hardware will restore the truck to normal gasoline operation.

[abus319]

We used these conversions on the farm in Okla, and they worked quite well. I would encourage you to leave it in place. Especially if you have propane or butane on the ranch. If not I might be interested in it for my "60".