Would the Dash01 method be a reasonable risk for head gasket replace on 173k m20 that has no reason to suspect any other head problems like valves?

http://www.bimmernut.com/forum/printthread.php?t=39906

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Post by Dash01. See link above. Thread subject was on 535.

"If it's just the HG itself, that should run ~$50-63, plus ~$3 each for the 14 head bolts, which should be replaced per the one-stretch rule.

The multiple gaskets kit costs ~2X more, though, if you want/need to do more gaskets than just the head. Call BMA for a quote, although your local parts guys can probably get a Reinz or similar kit for the same price, same day and no shipping charges.

To do just the HG and assuming no other work on the head, and that it's straight, should just take a few hours.

It's probably possible to unbolt and raise the head by hoist without removing the wiring harness, if the harness retainer bracket is removed from the firewall to make enough slack in the wire to the computer brain, and/or by unplugging it from the brain. This would entail unbolting the timing chain (at TDC), the exhaust pipes, and the wires to the starter motor, but leaving the intake and exhaust manifolds on the head. A standard hoist or overhead winch should suffice. Raise the head just enough to see and clean the surfaces, so good lighting and mirrors would be helpful.

When putting the head back on, make sure you have both dowel pins in place, to hold the new HG in position: I used old golf club shafts for this, thin and flexible, inserting them through the head and down into the head bolt holes in the block, to guide the head into place as I slowly lowered it to mate with the block."
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Few questions: How to tell if head warped? Assume this approach would work on an m20 in an 89 525?

Effort and cost so low for a DIY job that taking a chance that head is OK seems like a reasonable risk. I've done head gaskets on BMW 2002 and Nissan 4 cylinder so m20 doesn't scare me so much.