Certainly looks like the other owner was saving on coolant ! As an alternative to prepping the cover with acid,it could be media blasted if you have access to one.I have used beach sand for a "gentle "clean of alloy.Looks like some ferrous deposit in the upper right,pick it out with a scriber. Last time I shocked myself with the cover price it was several hundred $,have fun.Hey Grumpyone, I was going to get the machine shop to give it a bath for me, but now maybe i’ll have a look around for a tub I can submerge the block in...
Re: timing cover, I never thought of repairing it. I thought it was proper r**ted but i’ll re-assess. Found this hidden damage on the inside:
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