Flushing engine coolant jacket ?!

hate to be the Debbie Downer here...but maybe got the sequence mixed up... this might be the hard way....and yes anything is possible..
-i would have tried some radiator, coolant system cleaners before hand...mostly caustic solutions i think, then flush etc...

Folks have done that. Be aware of the possibility of forming new leaks because sometimes that crud is hiding latent weak spots in o-rings, plugs, etc.

My experience has been the taking the radiator apart and rodding it out does much more good than a chemical flush. If the cooling system has had oil in from your comment about oil cooler leaking, flushing with something like Tide cloths washing soap has been reported to work well. But that might do more good circulating with the engine running and warm than trying pump it through the block at this time. But if you suspect muddy water has been put in the cool system that might come out better now with a great volume of water..

use laundry detergent its not as harsh as the proper flush products. just use double the rate for top loader washing machine.

yes they are caustic based and so is laundry detergent.

lanotec also make a citrus oil based cleaner called citra-force it works very well and is ph neutral. not sure if you can get it overseas but there are several similar products on the market.

Thank you for the feedback, I actually did the good ol laundry detergent trick and then went and worked it hard for a few hours. it helped a bit but didnt really do enough.... s an update from the first post, i took it into the RAD shop, they said that the coler is on its way out. the top part of the core is sweating and could let go at any moment. so does anyone have opinions or options on a new RAD core cause WOW are they ever expensive. The RAD shop quoted $3700 to repair it, the local aftermarket Cat supplier (union tractor) quoted $2500 for just the core if i do the work myself. Seems crazy high to me. If i could source the parts i could probably build my own core as im a competent tig welder and fabricator but i have no idea where to search for parts. Thank you to anyone who can lend their thoughts on this !

its a lot of work to make a rad. but what you could do is get a modern aluminium rad from say pwr or aussie dessert coolers and fit the old sides and tanks around it so it looked the part. these australian companies both do custom stuff for all sorts of applications. ally rads are much more efficient you look at what a current model v8 has compared to what they used in the 60s its half the thickness.

by the way you dont need the oil cooler actually but what we did was get a trans cooller for a landcruiser and mounted that in front of the rad and it works

depending on how rotten it is you may be able to flow solder over the bad spots and put off the replacement. the best is a replacement core or a modded modern unit.