I have a couple original in the box GM 1184LW Bowtie blocks ( unmachined ). I purchased 20 of them and built LW Late Model oval track engines out of them, I think the actual weight is about 40-50# less than a standard Bowtie block and this weight reduction was in then casting not machining. I paid $4500 for them and will sell for that as they are no longer available.
I also have a good selection of Uniboring Cup style blocks ( SB-2 & 18* Some Compacted Graphite ), cranks, rods, pistons, cams, heads etc. 23*, 18* and SB-2.
I ship small parts out , a couple time a week and big stuff once a week.
e mail ;
mancinelli@att.net
Sorry Dave, bore might be rough 3.900