MILD THUNDER

iTrader: (3)

Couple questions I have about the morel lifters. For starters, on their website, they list a HYD roller lifter part #, that says fits 1988 and newer blocks. Then there is another part#, that lists 1987 and older blocks. I believe GM was still making the Mark IV style blocks up until 1990 or so?? Did they make changes to the block or something? This is the first i've seen a set of lifters specified in this way. I did not know a production 1987 454 mark iv differed from a 1988 production 454 mark iv block?

Also, are the NON HI-RPM lifters also .300 taller?

Really cant find much info on these online. It seems they make a street lifter in the 350 dollar a set range, a race style lifter in the 600 dollar a set range, and a HI-RPM series in a 700 dollar a set range??

1BIGJIM

iTrader: (1)

Call RMBUILDER

Call Bob Mandera at 585-654-8583

rmbuilder

The two parts #’s referenced would be the set #’s 5288 (1988 Newer) & 5374 (1987 older). There were machining differences in the two parts, however they have recently revised the manufacture consolidated them into the one 5374 part #. That being said there are significant material, and dimensional contrasts separating the street performance/Race/Hi-RPM lifters. We do not recommend the street/performance lifters in any marine application largely due to the use of a .700” roller wheel vs. .750” for the Race/Hi-RPM versions. The new .903” Hi RPM versions will support a .810” wheel.

The race version are also .300” tall and a direct drop in on any MK IV, Gen V/VI,Dart or Merlin block.

The pricing listed in your post would seem a bit high.

Regards,
Bob

MILD THUNDER

iTrader: (3)

thanks Bob. That cleared up the questions I had.