there are dozens of active heat exhanger part numbers for mercruiser (and multiples more of inactive part numbers) and most of them look similar. move a connection here, rotate a connecton there, etc. if your looking to replace a heat exchanger, replace it with the same part number.
if your putting a HX on a boat motor that has hours on it, you may run into issues. if you have run salt water thru the motor, the rust has already started.
Yes it is, I didn't know that.So with a alpha water pump u can only go with a block and head only system?
Thats the info iam looking for because this set up is without it.
Also would I have to change thermostat housing and us block off plate on manitfolds?
I'm running a SeaKamp SK4802 (half system for V-belts). If you have a serpentine belt, use part number SK4806. The system has been flawless from day 1.
a quick way to mount that HX on your V6 would be using the 1" elbow on end from the raw water pump, the two 3/4" straights are raw-water out to your exhaust manifolds. the big drop tube would go to the lower radiator hose, and the short horizontal unit to the T-stat. The small line on the expansion tank would go to the lowest part of the lower radiator hose (fill line).
the following is a quick link that I found that should point you in the right direction.
remember, in addition to the HX, you need the mounting brackets, a bunch of formed hoses and a new T-stat housing. in many cases it is much less expensive to simply buy the kit vs piecing the kit together.