Slant Six Build Ideas

Oh no doubt... Mine IS being "Built" in my home garage.... by nobody other than ME.
but I am having more machine work done to it than I have had done to the 1st 2 Slant engines I overhauled ~30 years ago..... 1st time asking for the block and head to be milled more than "just enough to assure a good seal".... (my block only took 6-thou for that to happen, I went 30-thou) 1st time porting a head, 1st time CC'ing one, 1st time I am dealing with O/S valves, on any engine I have built, V8s included.... I don't have a mill or a boring bar or the tools/fixture to press piston pins, or anything like that..... so I have to rely on a machine shop for all of that.

and most here will tell you not to shoot in the dark and guess how much to shave off block and/or head..... measure as you go or you might get to where it will not run on pump 87. Be careful there. myself I'm going for "all I can get" and still run pump 87. 89 and 92 are incrementally way too much more than what 87 costs now a days... IDK what ever happened to a 10 cent differential. Sometimes I see 60-cents more for premium vs 87.... for EVERY gallon, and that would be on EVERY fillup.. no thanks. I'd have to double power and MPG both, to make that worthwhile. having to run premium will make a 20MPG combo seem like a 13-14MPG combo if you "could have" run 87. Make sense?
though MPG isn't the end-all, cure all for me, I am going for the best I can get "for what it is"
I don't have an exact number yet// but between the block and head, I'm guessing I will wind up at around 80-thou shaved between the block and head combined but the actual number remains to be seen.

20-thou of milling will only put you back to stock compression because of the bigger thickness of any aftermarket head gasket you will find..... the original was a shim steel that was only 20-thou thick. most currently available head gaskets for a slant 6 are 2x that.