Thermostat bolts

[91gmblack]

Hi, quick question:

What size thermostat bolts I need to replace my thermostat and housing for a 1991 5.0.

I want to put new bolts in and my "factory manual" is no help.

(I'm replacing the lower manifold gaskets and seals, and want all the hardware available at the time I do the job).

Thanks in advance.

[turbo2256b]

They are the same length as header bolts. If you can find some with a reduced 12 point hex work great, hex size it makes removing and replacing the thermostat a bit easer. 5/16 coarse thd. The 12 point head gives more posithion to engage the wrench on the lower bolt. Sould be a 5/16 head if its a reduced hex.