Conversion questions

[Chevy Truck Guy 86]

I have a '86 right now but I want a 78, so I thought couldn't I keep my '86 frame and drop a '77-79 cab on there? But would it work to put a '77-79 cab on my '86 frame? Also I have an '87 box so would that match up with a '77-79 cab? Will I run into mounting issues and a messed up body line?

[zieg85]

I have a '86 right now but I want a 78, so I thought couldn't I keep my '86 frame and drop a '77-79 cab on there? But would it work to put a '77-79 cab on my '86 frame? Also I have an '87 box so would that match up with a '77-79 cab? Will I run into mounting issues and a messed up body line?

It is all interchangeable with subtle differences in frame mounts.  You have to use the mounts meant for the frame.  The front frame horns differ between the 73-80 and 81-87.  That is the beauty of our era of trucks/

[Chevy Truck Guy 86]

I found this post off of a different site:

You still have to consider the way fenders mount to the cab. 73-80 for sure interchange, 81 up interchange for sure. Difference being the 73-80 have the hood and cowl as 1 piece with the older style springs and hood hinges. 81 up uses the newe style hinges and the cowl is seperate from the hood.
Also the body mounts and bushings are different from 73-80 and 81 up. But, the cabs do interchange on the frames without problems, SO LONG AS, you use the correct mounts for the frame, not the cab. So in his case, he'll want to use the 73-80 mounts and the cab will bolt right on.

What I got out of this is that a 1978 cab will drop onto a 1986 frame without troubles but the cushions won't. I know in my catalog there is a cab mounting set for '73-80 and '81-87 so if I put the '73-'80 cab mounting set I will be fine. So do you guys think this is right?

[zieg85]

http://forum.73-87chevytrucks.com/smforum/index.php/topic,9070.0.html  covers the difference in the front ends.  I thought you wanted a 78 so I thought you would have that style front end as well....

[werewolfx13]

You want the cab mounts for the year of the frame you're using....for an 86 frame and a 78 cab, use the 81-87 mounts.