Update: So took everything off the front, removed he broken bolt which was sticking out of the block and I was able to remove it by hand. Added new gaskets and bolts. Re-assembled and fired up today. No leaks. Will cool and check again tomorrow. Glad it is all back together. Thanks for all of your help.

A vendor named Totally Stainless has stainless bolts that they say is equal to grade 8.  They sell by the piece.


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

For the most part grade 5 is overkill in an automotive setting that is not suspension or stress related. Intakes, water pumps, PS mounts, AC dist hold down, oil pan etc need only the lower rating of a 2. I use 5’s also and clean all threads, male or female, but I know it’s not necessary. 

56 Vic, B'Ville 200 MPH Club Member, So Cal.

It occurs that what applies to the stainless available at big-box home stores (cheapest grade) likely also would apply to their base level zinc-plated steel.  So, I’ll use the grade 5.

6 VOLTS/POS. GRD. NW INDIANA

I personally would prefer a bolt to snap due to overtorquing rather than threads getting stripped or other damage occurring to the block.  The remains of a bolt that snaps can usually be unscrewed.  Stripping requires thread repair.
With stainless, everything will probably be fine but there is always a risk of thread galling.  When that happens, drilling out the remains is required and retapping may be required.  Also be aware that not all stainless is equal and the stuff at a typical hardware store is probably the lowest grade of stainless available.  ARP sell really good quality stainless and you can find other options at an industrial supply, although you will probably have to buy that hardware by the box, rather than only the quantity you need.

Bottom line, if you want the most trouble free, use zinc plated steel hardware.  The 23-28 ftlbs spec does fall in line with grade 5 hardware.



Lawrenceville, GA

This brings up an interesting point: The bolt that I robbed from my spare motor (to replace the one that recently fell out of my timing cover) was apparently ordinary zinc-plated (from a T-Bird catalog concours hardware kit).  When I stopped at a home-center store to replace it, there were 3 options: plain zinc, grade 5, and stainless.  I couldn’t decide,  so I bought one of each.  
So, which to use?  I don’t have a trailer-queen/show car, so function is more important to me than appearance.  Stainless won’t rust, but could possibly seize in iron threads (unless the gummy thread sealer used for a coolant passage acts reliably as anti-seize?), and, maybe stainless is more brittle/likely to snap if over-torqued (?). If ‘I’ made the mistake of using the 3/8 torque spec. on the 5/16 bolts (as did the O.P.) so could others.  So then, wouldn’t ‘overkill’ (grade 5) be justified in that location, or would it be more trouble if the threads in the block were somehow stripped, rather than just the bolt snapped off?  A quandary.

6 VOLTS/POS. GRD. NW INDIANA

Looks like I really dodged a bullet!  After one of my timing cover bolts fell out recently, I went back and tightened all the rest, but mistakenly used the torque specs. for the larger lower bolts on the smaller ones also.  Likely the paint/dry heads/rust must have compensated some.

6 VOLTS/POS. GRD. NW INDIANA

Thanks. I will get it towed. Probably why I broke it. I was torquing it 30lbs.

It will leak without that bolt installed.  Best to have it towed.

The spec I see for those 3/8" bolts is 23-28 ftlbs.  Any through holes should use thread sealer.  I don't know if those upper bolts are blind or through.  Lot's of people use regular hardware store grade stainless bolts, which aren't very strong but seem to be strong enough for that purpose.  If you want a graded bolt, probably grade 5 is overkill for the application.



Lawrenceville, GA

It is one of the long bolts that go thru the water pump and timing cover. By measuring the broken bolt I think there is about an inch gone on the end of the bolt. Will it leak if I put it together and drive it to my mechanic? What torque do you recommend for those 4 long water pump bolts? Do you put a dressing on the threads? Also what grade of bolts would you use? I know alot of questions. I just want to make sure this won’t happen again.

The ford truck shop manual recommended 35-40 lb of torque. I put it to 30lb and it broke the bolt.

Thanks again for all of your advice. I appreciate it.