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Bellhousing for 402 bb

1K views 4 replies 5 participants last post by  M&M CUSTOM 
#1 ·
I am changing a 70 402 bb to a 4 sp. the flywheel is or will be 11". Will this take any GM bellhousing for that year or is there a certain bellhousing I should be looking for. Also the same for the flywheel.
 
#3 ·
Some vehicles require a different bellhousing from others due to clutch linkage placement, etc. If you're using the 11" clutch, you'll have to use the larger 168-tooth (14" diameter) flywheel, and that wheel won't fit into some of the smaller bellhousings that were designed for the 153-tooth (12-3/4" diameter) wheels. For example, first-gen Camaros used the small bellhousing with casting number that ends in -403, or the large housing with a number that ends in -621. The 11" clutch won't fit with the -403.

Another potential difference in bellhousings is the size of the hole where the transmission front bearing retainer rides. I don't remember the exact dimensions, but there is a small difference which can cause misalignment if the hole is too big.
 
#4 ·
jimfulco said:
Another potential difference in bellhousings is the size of the hole where the transmission front bearing retainer rides. I don't remember the exact dimensions, but there is a small difference which can cause misalignment if the hole is too big.
As far as I'm aware, there are only 2 sizes of front retainers. The 'car' retainer is smaller, and more popular. It is also the same size as the retainers used on the old SM318 3-speeds, in cars or pickups.
 
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