Cat R4

would anyone know the year of a R4- #6G1335SP ??

My listing of that model is a little blurred but it appears to be the first produced model of 1941. The SP is for special parts, something that was different internally that required attention on the assembly line. Most commonly different gearing.

thanks-old magnet---this is the first time i have ever even heard of an R4--i used to own a R2--6J102

The Cat SNID book says the R4 was first produced in 1935 so back then there probably wasn,t that many produced like today so the 1941 year for yours could be right.My Cat book only shows start up years for all the machines that Cat produced & the real early tractor year models that it was started is not even listed like the Holts & Best tractors & old fam equip. they made.