Trying to figure out the thermostat type on a 312 y block interceptor marine "dearborn"  as the thermistat housing was made by dearborn a standard 312 y block one does not fit it.   Anyone know what one dearborn was using?  spent hours at the parts store pulling them out and looking at them with no luck

Also have similar problem with the front crack seal thru the timing cover.   the stand y block has a larger diameter hole in it where the balancer comes thru.   the boat motor does not have a balancer only a pully.  the OD of the pully is smaller than the balancer.
needs a different front crank seal???

thanks