I want to put a ez drain valve on the oil pan for my 1995 454 Mag to make oil changes easier. Just wondering on the thread size so I can order a valve over the internet? I have seen many posts on the subject but Im still not sure on the size of valve I need 12x1.75 and 1/2x20 are the sizes i keep comming across. So if someone would be able to shed some light on which size it is that would be great!

Is your engine a Gen V? I think 1995 engines are Gen V but I'm not sure. If so you should need the 12x1.75

I just purchased one of these myself but my engine is Gen IV block with a aftermarket Gen IV oil pan and it is 1/2x20

Can somebody else with more knowledge than me chime in on what Z06 needs?

Im not sure and my boats in storage right now. How would i know the difference? Would it be labled or stamped somewhere? All I know off hand is that its a 1995 fuel injected 385 MAG.

If you can get to your boat you can get the serial number off the left rear back of the engine block and look that up and know for sure what Gen it is.

It is most likely a Gen V since its a 1995 or possible a Gen VI but either way you would want the 12x1.75

There are a lot of guys on here that know all the different years and what Gen blocks Merc used so I hope somebody else will post here.

I have a 95 502 EFI, in a 96 hull,and it is 1/2"X 20. I installed a drain hose that I purchased from Overton's. I believe that the Gen V motors are standard and the Gen VI motors are metric.

It will use the 1/2 x 20

The same merc part # 10-49956 is listed for models going back into the 1970's. Metric didn't start until 1996.
http://www.mercruiserparts.com/partsByNumber.asp

Great info again Griff!

CP Performance says all Gen V and Gen VI engines are metric and the Gen IV are 1/2x20. I got mine from CP and I bet the OP was looking at CP Performance website also.

I knew somebody on here had the correct info!

The Gen V's vary. My 1996 525SC was a Gen V and used the metric.

griff,wasent 96 the first year for gen6?

Yes, but they never used a Gen VI block for the 525SC and Merc used the newer oil pan with the metric tapped drain.
http://www.mercruiserparts.com/selec...asp?type_id=8H