b61fred 18 Posted October 30, 2017 I'be got my self in a project that I know little about. Someone else has removed the 431 gas engine and trans from this truck. The engine is pretty much junk. Add in the fact parts are almost non-existent for this engine. Has anyone here had any luck installing a "B" model 673? Quote Share this post Link to post Share on other sites
j hancock 10,963 Posted October 30, 2017 No real details but here is one that is done. https://www.hagerty.com/articles-videos/articles/2017/02/20/mack-truck 1 Quote Share this post Link to post Share on other sites
b61fred 18 Posted October 31, 2017 Thanks for the article. I think the 673 is pretty close to the original engine in size. I guess I will have to get the tape measure out and get started. 1 Quote Share this post Link to post Share on other sites
thomastractorsvc 1,363 Posted November 23, 2017 On 10/31/2017 at 5:01 AM, b61fred said: Thanks for the article. I think the 673 is pretty close to the original engine in size. I guess I will have to get the tape measure out and get started. what did you find out? Quote Share this post Link to post Share on other sites
b61fred 18 Posted December 16, 2017 Sorry for the late reply. The engine is about 6 inch longer than the gasser. Other than that its pretty close. I also found the 673 from a b is very close to the steering box. There would be no way to install a R model engine unless the oil filters were remove mounted. The A 50 frame is about 6 inches narrower than the B frame. Morgan Quote Share this post Link to post Share on other sites
Maddog13407 2,083 Posted December 16, 2017 slide a little 12 valve Cummins in there. always wanted a little A model with a Cummins 2 Quote Share this post Link to post Share on other sites
