We`re rebuilding the 270 horse 350 for our 71 coupe. We torqued the head bolts to 80 ft lbs.... then realized that is for big blocks. Our small block should have been torqued to 65.
We loosened them all in reverse sequence order, then re-torqued to 65.
Question is... will the head gaskets be OK? Did we damage them? They are Fel-Pro gaskets.

 

It will be fine. I've read here on CF of a guy re-using used head gaskets. Claimed he did it before with no ill effects. If you can get away with that, 15 lbs over shouldn't hurt anything.

 

shouldn't hurt anything.

 

As long as the gasket hasn't been heat cycled it will be just fine....

 

Thanks gentlemen... (sigh of relief)... then we shall continue with the re-assembly!

 

I would like to add an appropriate tip here when installing any OEM or aftermarket iron heads on the SBC's using the factory head bolts. Basically this is for the 100% stock-appearing builds.

Pick up some head bolt washers and use them with the factory bolts, for some years now we've been repairing a high number of damaged head bolt bosses. Most lightly damaged, others more severe. (See some of the photos below)

We use washers, photo also below, that allow the use of the OEM bolt lengths, will not have any adverse effect on the number of threads into the block.

These washers will help save the head castings AND keep the Torque load in check. You also cannot see them after the units are painted! They are NOT the conventional 1/8" thick pieces, they are thin but recommended in 70#/75# Torque load situations.

(Add) I could never understand how G.M. decided to use head bolts with built-in washers on the BBC platforms but not on the SB's, makes absolutely no sense me to this day! Even the newer SB's were corrected with this "error"!

Thanks, Gary in N.Y.

P.S. Just to answer the main question, you will be fine with the retorquing and the original gaskets. Make certain the bolt threads have been sealed?

 

glad i read your post.when i torqued the bottom row of head bolts on my small block with pro comp iron heads just about every bolt boss cracked. my engine builder said i didn't need to use washers. they felt funny at about 55 lbs. of torque but otherwise went to the 65 i was using.frustrated,i got the thin washers you talked about and took them up to 65 where they were supposed to be.i'm about to drop this engine in and i'll be worried about this.blocked was decked so that should not be the problem. any thoughts on this? thanks

 

 

Hi "old", that blue printing is real easy on my old eyes, I like it!

I've lost count of the number of SB heads we've seen/repaired over years of doing this for a living. Way too many broken bosses?

Thanks, Gary in N.Y.

P.S. I wanted to put one more picture in my post above, I didn't have it here earlier. This is here now for repair, should be no problem, this is one of the more damaged pieces we get to fix. Every build we do now gets those washers in my photo above. We actually order them by the thousands now, big hit with all the Flathead Ford guys and more.

 

Glad I didn`t see anything like that on ours! This is the first re-build on this (number matching) engine, seller says it only had close to 100,000 miles on it. Inside was pretty clean. Long trusted local machine shop with "old school" machinist.... one of the best in the area, did the work for me. Sadly though, he says they aren`t doing many gas engines any more, they make too much money on big diesels.
The head work was EXpen$ive! That`s why I was so worried about ruining them. I probably could`ve bought a pair of heads cheaper, but then these are the original ones.

 

thanks for the reply gofast. that last photo looks like one of mine. most had small cracks.i sealed the bolt threads and used a q tip with sealer to seal the bolt holes. got everything to 65 and will hold my breath when i fire it up. had to use a trouble light to see them