When you get the block on the engine stand, before doing anything else, you'll want to stick a long screwdriver down into every coolant passages and scrape, scrape, scrape, scrape and scrape some more. A long pointed tool can be used to lightly jab at the bottom of the water jackets to see if there's any residue caked there. The washing vats seem to turn some of the sediment at the bottom of the jackets into a hard, but fairly porous material that can be poked, prodded and scraped away, but it's time consuming to get it all..... and you'll want to get as much as you can.

Maybe you'll get lucky if the machine shop did a really good job and got everything out.

Frank

'89 [color:"white"]G-Raider[color:"white"] [color:"black"]Supercharged 3.0L, MegaSquirt 2, lockup A/T, 2.5" exhaust, 172k, Cibie H4s/Oscar SCs, Hella Micro DE fogs, Cobra CB, Superwinch hubs, LSD rear/Aussie Locker front, Bilsteins, Lifeline AGM, Rust-Oleum