casting # 4x151981

[rogerv6]

Who look this casting # 4x151981 in stg2
block before

 

[turbodave231]

That is an experimental block casting number. I had a 4.1 S2 on-center block like that a few years ago.

Dave

 

[S2V6RACER]

That casting ## block is what is in my car now.

 

[Ron Tarabori]

I've had a couple of those blocks but never found any info on them. I think Kendall has one I sold him. Early on center, non crossbolt with internal oil pickup. I couldn't see any visible difference from the early 153 casting.