To start with the number 53006921360 you posted needs the 360 droped off the end because the 360 is the cubic inches.
You have one of the common engines. When have you ever seen a standard transmission in a late model motor home?
Read the following information then change the harmonic balancer.
1989-’90
The 360 got a new block with three cast bosses in the valley for the roller lifter holddowns. Although all of these engines had fuel injection, they continued to use the cam with the long snout along with either the eccentric or the special cup-shaped washer. Both intermediate cam journals had holes to meter oil topside. The 318 and 360 cams are different and shouldn’t be interchanged. The most common block castings are 4315830 and 53006921. The later block (53006921) was used in ’91, too, so check the oil filter boss to see whether it’s a ’89-’90 or ’91 before using it for either application.
1991
This was the year of the corporate oil filter, so the 360 block was changed along with the 238 and the 318. The oil filter boss was 0.250" shorter so both the plate and adapter were modified accordingly. The rear main cap had a dowel pin and may or may not have the recess for the o-ring. The cap was still grooved for the rear pan seal. It had the old style ears for the motor mounts. The block was the 53006921 casting that was carried over from ’90, so once again you have to physically check the length of the filter boss to be sure if it fits a ’90 or ’91.
By the way the stroke on a rv is the same as the pickup. Only difference that was done was a camshaft.
That makes me feel better. I believe the non magnum roller cranks were the same as the non roller 360. I don't think they changed until 92 for the magnum roller engines.
