Info needed: JXD versus JXLD

[Lynn Eades]

Darryl, I have a book called Motors truck and tractor repair manual. It says the JXLD has a 1/4 inch longer stroke. and is a 339 cu. in. as opposed to a 320 cu. inch. JXLD is 131 h.p. while the JXD is only 84 h.p. Quite a difference. The big engine has a 6.9 to 1 comp. ratio while the small one is only 6.5 to1.
The bores of both are 4 inch. The JXD is 4 1/4 stroke and the big engine is 4 1/2 stroke. This might mean that the pistons are not interchangeable (piston height) or the rods are different? Cranks are different? Look carefully. The JXD engine was used in many trucks not heard of now and seems to have originated in 1936.