I marine engines from late 80's to date there was different intake bolt angles used fro the center bolts. The early castings used for marine use had the std. angle and the later ones used the tbi style angle.needforspeed66gt wrote:gem wrote:That's odd as the head I have here in my shop has the center intake bolt holes on the different angle and I can't recall ever seeing a 217 or its sister casting the 083 with a different intake bolt configuration.The 217 head doesn't have the 45* center intake bolts like all the other TBI heads.
I'm in Canada so it might be a Canadian thing we have been known to have different GM castings before.
Odd...I just used a set on a motor this week and the intake bolt pattern and angle was standard SBC + a 69cc chamber.
This was due to the intake manifolds being used by merc maring volvo-penta etc.
They did standardize in the 90's to just 1 bolt pattern when marine engines started to use injection and that was pre vortec head design.
Most of the marine stuff I see now is the new style bolt pattern. There is no reason why they did this except the number of boats that had older engines that needed replacements and without totally changing everything the intake was left unchanged.Basicly a cost saving measure to sell of inventory. At least thats what the merc marine reps tell me.