For those of you following this ...<br />Got engine #2 in the other day,to replace #1 that had no compression in # 3 and # 4 cylinders.<br /><br />Found it had 18mm sparkplug holes.Compression okay.Called rebuilder,he calls back and tells us what 18mm sparkplug to use.Put mechanic back on exchanging manifolds etc.<br /><br />Then got thinking .... head should have 14mm plugs and a 5/8 swivel socket barely squeezes in ... NO WAY a 7/8 socket will let us install an 18mm plug.Called rebuilder.<br /><br />Engine # 3 now sits on the floor,has 14mm plug holes,is waiting for compression test.<br /><br />I know you want to ask....so here's 4 reasons ::<br />Rebuilder does excellent on marine GM engines.<br />Genuine Mercruiser replacement is $$$$<br />The 3.7L is sort of a hybrid engine,and the company is working with us.<br />We also have about 14 hours of labor reimbusement involved...even if it is $15.00 below our billing rate.<br /><br />Just to keep you updated.<br /><br />DHP