How to tell if engine in my rig is a 401 or a 360..??

[79 FSJ]

The Vin codes out a 360, but the PO has done some mods that make me think that the engine rebuilt he did may have been a bit more than just a rebuild and maybe a swap...

I have been doing some research and have not been able to find any info on what to look for... I have done alot to this thing and have been trying to get the milage up and with all the things I have done I have only be able to muster out 10 mpg... I would love the usuall 12-15 from a 360, but the current 8-10 tells me that this may be a 401...

thanks for the info...
Dave
79FSJ

[Retro93]

Hi 79 FSJ,

It's pretty easy to determine which AMC engine resides in truck. All AMC engines have the cubic inch displacement information cast into the side of the block [drivers side] under the motor mount. You can simply crawl under your rig with a flashlight and take a look. I hope that you see the following: 401. :D

Hope this helps.

Regards,

Kim

[Marvin Gates]

I was hoping when I looked at mine but it had a big 360. M.G.

[79 FSJ]

I am going to check that first thing when I get home,... and I will have a big smile on my face if it reads 401... but if not, I will just keep trying to get this milage up...

Thanks
79FSJ

[Bob Barry]

Yah, the only thing that 8-10mpg tells you is that you have an FSJ... ;)

Good luck finding that "401" on the side of your block. It is hard to see it under the motor-mount bracket there, though...