4.3L versions

[Lewis1111]

Hey guys wondering if any one know the difference between some of the 4.3L applications. I see most resellers of long blocks have a split from roughly 1996-2007 and then 2007-2011. Casting numbers change as well but I can’t see what the difference between these blocks would be. Would a reman long block from the earlier version fit as a replacement for a engine in the newer range ?

 

[dubs283]

Would a reman long block from the earlier version fit as a replacement for a engine in the newer range ?

Maybe, there were thirty ish changes to the 4.3L engine over the years. Some big some small, the main issue I've seen is the pto end of the crank had some changes and not every flywheel mounts up correctly

Best bet is to find a casting number that corresponds to the one you are replacing

 

[Scott06]

I know one of the changes in block casting was the metric blocks with 090M casting vs 090 the M or metric block used M10 metric fasteners for side motor mounts, starter, and flywheel cover bolts, all else was sae threads…completely interchangeable with a few new fasteners…

@Scott Danforth may have some ideas he did a write up on 4.3 casting numbers

 

[Scott Danforth]

2007 and later, full metric
1996-2006 mixed bag.

if you have a 2007 and later boat, get a 2007 and laster long block

 

[achris]

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