When people do large head shaves for compression, ive read that timing chain rattle is normal and expected.

To avoid this, has anyone ever tried putting in an extra link in their chain, or even a half link?
(these exist for the ford 85 Laser at least)

How far can you shave before you really make a mess of the head and end up causing valves to hit pistons?

Not too sure about adding a link. maybe remove one....

I had a AU with 12.5:1 comp. ACL flat top pistons and 0 deck height and .040 removed from head. Pistons then modified with deeper valve reliefs to give more clearance. Never had an issue with chain rattle. but I also used a new rolon chain and new guides tensioner etc

I think I misspoke.
Indeed you would need to remove a link, and perhaps add a half link.
Not, add them

people take huge amounts off the heads to gain compression because they don't want to or cbf rebuilding the bottom end with the right pistons to suit the comp there after..

I agree and aptly describes what it is I am going to do

it will work to a point, but if you already have a lot of kms on the std bottom end , by raising the comp ratio from shaving the head you will also loose some of that compression via blow by past those old rings..

Copy that. You're pretty spot on, as always TROYMAN. Appreciate your comments. Fortunately my old EA only had 149k on the clock (not that it matters) and the EF Tickford engine that is copping the work is only 120ish on clock.

Im certainly NOT going to shave 50thou or even close. Im aiming for 30thou, but was asking as a matter of curiosity.

I am going with a Camtech 845 or 842.
Ef Tickford 30thou shave and AU MLS gasket.
Crow valve springs
Suitable High stall torque converter
4:1 Diff <- apparently this really matters (and this is the ratio I have)
J3
Perhaps injector upgrade depending on what I learn from the above.

What do you think? Seems like a balanced package in the sense of the old (cam/carb/extractor) upgrades of 'yester year'.