Standard vs metric

[tonyjh63]

Ok, so I ordered a remanufactured engine from Promar a while back (4.3 Mercruiser, carb). We couldn't give them a casting # off the block, so we told them 8 bolt intake, no crank-sensor...
Well, my mechanic tells me today that the new engine is all "standard", while my old engine (cracked head, two cracked manifolds) is metric, and that the oil pan won't work.
He's going to contact Promar tomorrow to discuss, but what are the options here?
Thanks for any input!

 

[Scott Danforth]

remember, there are 4 generational changes for the 4.3 from when the vortec heads came out (8 bolt intake)

so, identify what you have and what you need by the block casting number

1996-2000
2001-2007
2008-2015
2016-today

 

[Scott06]

the 4.3 that was original to my boat was a 4.3 that was metric. Not sure why gm did it this way but the side motor mounts, starter bolts, and flywheel cover bolts were metric, all other fasteners were US.

ordered the correct US starter bolts online, a trip to the hardware store for correct grade 8 US fasteners , bought grade 8 studs to replace the 3-4 shouldered studs they use on flywheel cover and side motor mount to mount fuel filter.

on the oil pan , just find out which one you need and buy one. You may need a stamped steel one vs the cast aluminum thta was on my metric block. Michigan motorz has oil pans and does rebuilds they may have a used take off for you. If you have an extra cast oil pan sell it on ebay they are not cheap.

get the casting number off your new engine someone should be able to match up the oil pan.
@achris has some experience with oil pans on 4.3 he may have the gm part number for the marine pan and be able to help you

 

[tonyjh63]

Well, crap...mechanic said this whole engine package is wrong...more suitable for an '80s hotrod S-10 than a boat engine. Non-roller tappets (flat tappets)...?
So...he's sending both engines to them...mine with cracked block, and the one they built for me.
Ugh!

 

[Scott Danforth]

Well, crap...mechanic said this whole engine package is wrong...more suitable for an '80s hotrod S-10 than a boat engine. Non-roller tappets (flat tappets)...?
So...he's sending both engines to them...mine with cracked block, and the one they built for me.
Ugh!

Flat tappet is 1985-1987

However NOT metric