Bell Housing to Block - What Size Bolts?

303Radar

Well Known Member
Supporting Member 2
I'm going to pick up my engine today and I'm going to try to mount it in engine bay. I have new bolts for the motor & transmission mounts.
However, I realized, I'm missing one key set of bolts, bell housing to engine.
Besides getting grade 8 bolts, what size should they be?

Thanks!
 

pvs409

Well Known Member
Supporting Member 11
The bolt size is 1/4 inch for the bell housing to block.
Assuming you are using a stock style cast iron 552 bell housing or a 553 aluminum bell housing, the bolts are:
5 - 1/4" by 1 & 1/2 inches (I think the originals were 1 & 3/8")
2 - 1/4" by 2 & 1/4 inches (one per lower side of the bell housing)
I have stainless on mine with stainless lock washers on these sizes.

If you have a horizontal mount starter there is 1- 1/4" by 1 & 1/2 inch from the bell housing to the upper starter.
There are two more from the starter to the bell housing -also 1/4 size - I have a vertical mount starter so I can't check the length.

Paul
 

303Radar

Well Known Member
Supporting Member 2
The bolt size is 1/4 inch for the bell housing to block.
Assuming you are using a stock style cast iron 552 bell housing or a 553 aluminum bell housing, the bolts are:
5 - 1/4" by 1 & 1/2 inches (I think the originals were 1 & 3/8")
2 - 1/4" by 2 & 1/4 inches (one per lower side of the bell housing)
I have stainless on mine with stainless lock washers on these sizes.

If you have a horizontal mount starter there is 1- 1/4" by 1 & 1/2 inch from the bell housing to the upper starter.
There are two more from the starter to the bell housing -also 1/4 size - I have a vertical mount starter so I can't check the length.

Paul

The transmission is a 4L60 and my main goal is just to get the engine and transmission in place so I can start routing lines, wires, put the fenders back on, etc. Since the transmission isn't drilled for a top bolt, I'm guessing I'll need 4 of the 1/4" by 1 & 1/2 inch bolts.

I don't have a new starter and may opt to rebuild the original, but that isn't a right now problem.

Long term, I will probably get stainless, (lock washers for sure), but for now, I just want get things in place and don't want to beat up my shins walking around the engine.

Thanks Paul!
 

303Radar

Well Known Member
Supporting Member 2

tripower

Well Known Member
Supporting Member 2
Bolts are 3/8-16. As Mike said if using spin on adapter you need to use a shorter bolt so as not to damage the spin on adapter. Easy way to do that is to run a bolt in prior to installing adapter to verify length or use a rod, wire, smaller bolt bottomed out on adapter mark and measure.
 
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