Today, I looked up the OEM (original equipment manufacturer) part numbers for my 1969 Cadillac Commercial Chassis Ambulance engine for a reference point. I then went to Rockauto.com and put in the information for my car, and found the belt part numbers. To my surprise, the part descriptions differed from the original sizes listed in the Cadillac parts book. I then went to the Gates.com website, and searched by application, only to find the same information. Then I tried putting in the OEM part numbers, and it came back without any changes. Knowing that 1/2" or 3/4" can make the difference between a belt fitting properly, I placed a call to a friend at a local auto parts store. I gave him the belt dimensions from the parts book, and he was able to give me the replacement part numbers within a very close tolerance. Only one of the belts that was "recommended" by the Gates website actually was an acceptable substitute. If you need replacement belts, I suggest that you try to find the original factory specification size, and have that converted to a belt number. My friend explained that some sizes are not that popular, and the catalogs today, will round the size the belt up or down so the stores don't have to carry such an extensive assortment.
For the 1969 / 1970 commercial chassis ambulance, the belt numbers are as listed below. The only differance between the ambulance and the hearse is the alternator (generator) belt length is different. I didn't have that part number available to me, so it isn't listed below.
A/C & Power Steering pump with 2 belts.
1602011 (GM)
7590 (Gates)
3/8" x 59 1/2"
Generator
1489483 (GM)
7650 (Gates)
15/32" x 56 7/16"
A.I.R. Pump
9433744 (GM)
9463 (Gates)
15/32" x 46"
For the 1969 / 1970 commercial chassis ambulance, the belt numbers are as listed below. The only differance between the ambulance and the hearse is the alternator (generator) belt length is different. I didn't have that part number available to me, so it isn't listed below.
A/C & Power Steering pump with 2 belts.
1602011 (GM)
7590 (Gates)
3/8" x 59 1/2"
Generator
1489483 (GM)
7650 (Gates)
15/32" x 56 7/16"
A.I.R. Pump
9433744 (GM)
9463 (Gates)
15/32" x 46"