2.3L ('83-'97) Head bolt torque -- how bad did I screw up?

[pentode]

Great info, well documented. I think we're all on the same page here - reusing TTY bolts that have stretched is a big risk. Reusing TTY bolts that haven't really been stressed is likely less of a risk. Pending verification by any metallurgists.
Check back in in 100k miles and let us know how it went.

 

[SenseAmidMadness]

In retrospect -- I should've used my beam torque wrench to check exactly how much force it takes to get the bolts to 90 degrees. Another d'oh! It's a heck of a lot more than 90 foot pounds. Downright uncomfortable even on the end of a 28 inch breaker bar leaning over the engine bay, especially after the 9th time in a row. If it's a linear ramp-up equal to the one between 50 foot pounds and 90 foot pounds, it's somewhere in the neighborhood of 125 foot-pounds. But it's probably not linear due to the bolts yielding.

I'm sure some engineer could give us a theoretical calculation. Just going by thread pitch the 90 degree rotation would attempt to force the threads an additional 0.375mm (or .0147") into the block...

Above my pay grade either way. I'm a semi-professional mechanic and only know just enough to be dangerous.

 

[pentode]

We're all here for the danger.

I for one am grateful you went through it just for the experiment. I love real world data.

 

[ForgedCrank]

Made a silly mistake in swapping my 1995 2.3 head gasket.

New Fel-Pro head bolts and head gasket. Threads were dry with no sealant though the bolt holes weren't perfectly dry.

I accidentally read an older service manual and torqued all the head bolts in 2 stages to 50 and then 90 foot-pounds.

Looked it up, and Fel-Pro as well as a ton of other places say I should have done the revised torque spec of 51 foot-pounds and then 90 degrees.

How big of a whoopsie? Do I need to get another set of head bolts and another head gasket and try again?

Just my 2 cents worth, not an expert.
I used these same bolts when I did the work on my 2.3 and they are TTY bolts. Frankly, it's not worth trying to re-use them. The entire set is only 25 bucks with free shipping. I see no reason to risk having to do another head gasket at some point down the road. If you are going to pull the valve cover, just replace them and move on.
My guess is it's way under-torqued and will eventually start leeching coolant once it gets enough heat cycles. I'd just pull the valve cover and replace them one at a time. Replace then in the torque sequence, torque each one to 50, then move to the next one until all of them are replaced. Once they are all replaced and at 50ftlb, do the 90deg second stage in sequence and call it done. It should be just fine as long as you do them one at a time and don't let the head move and break the gasket seal.
The worst part is getting the valve cover off.

FEL-PRO ES 72137 Head Bolt Set

edit:
Never mind, I didn't read the entire thread. It appears you already took the leap.