what size amp on alternator?

Also can look on the inside of glove box lid at the Regular Production Option (RPO) code list decal and find the 3 digit code # with the letter K.. eg.. K65 is 105amp.. KD9 is 145 amp... Post 'your' number for more info. If needed.

2 different ones for the truck...145 AMP WITH case spacer and without case spacer...also 105 AMP WITH case spacer and without case spacer...the 145 AMP is 5 5/8" diameter case.i believe the 105 AMP is 5 1/8" diameter case.just take the old one with you to the parts house,the clocking is different on them also.your old one may have some numbers on it.probably the bigger one.