X Head Assembly & Installation - Comments Requested

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Classic is a 'spensive place to buy from. You can get ARP's for $5 more. PN 144-3602 Note that ARP's have a very different lube, application, and torquing regimen. Maybe some else has a better cost source. It is hard to say if your present bolts have stretched or not, without some measurements and inspection; they indeed can be reused but we can't tell you here the condition of yours; just suggest possible problem areas.

I would expect (hope?) your shop would pick up on a poor head surface.
 
I'm installing the rocker shaft. A few of the lifters are applying enough lift to the rods that the shaft won't site flush. Can I assume that tightening the bolts will force the sprig down and allow the shaft to seat properly?

I don't see any other way to make this work.
 
Yes, tighten each bolt a turn each working left to right or right to left across the shaft.
 
Tighten them down even and try not to bend the shaft
 
Got it. Second question, the retainer looks to be rubbing the rocker. Should I file the tab down?
image.jpg
 
I just tighten to 25 ft lb. Don't file that's how the are keeps the push rod centered
 
Ya that's incorrect shows 17 ft lbs, 30ft lbs is for 3/8 bolt, these should be 5/16 and I would go 20 ft lbs, my 1970 manual shows small block 17 big block 25.
 
The factory service manual is WRONG! And 25 ft-lbs is TOO MUCH. The correct torque is 200 in-lbs or about 18 ft-lbs. If you have already torqued them to 25-30 ft-lbs replace them with new bolts.
 
IQ52 said:
The factory service manual is WRONG! And 25 ft-lbs is TOO MUCH. The correct torque is 200 in-lbs or about 18 ft-lbs. If you have already torqued them to 25-30 ft-lbs replace them with new bolts.
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Haven't torqued yet.
 
I have never broke a old mopar bolt, used them over and over and I'm sure over torqued a few hear and there, totally different story with bolts made for stretch to yield stretched a lot of them trying to reuse them.
 
IQ52 said:
The factory service manual is WRONG! And 25 ft-lbs is TOO MUCH. The correct torque is 200 in-lbs or about 18 ft-lbs.
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How is the FSM wrong and where did you get the other value from?
 
Some of FSM's were found to be wrong a long time ago.... presumably when a lot of bolts got broken! Max recc. torque for grade 8 coarse thread 5/16" bolt is 18 ft-lbs with threads lubricated.... documented in a lot of different places like this:
https://www.fastenal.com/content/feds/pdf/Torque-Tension Chart for A307 Gr5 Gr8 Gr9.pdf
The same table shows 25 ft-lbs for dry threads to get to the same tension level.

Good work OP! Looks like new ARP bolts?
 
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rumblefish360 said:
How is the FSM wrong and where did you get the other value from?
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I don't pull these things out of my arse when I post on this forum. I have experienced or tested this stuff.

Go to the factory service manual and look at the torque reference for every 5/16-18 bolt. It will be 200-210 in-lbs, 10 (oil pan bolts)-18 ft-lbs. And like mentioned above the rocker shaft bolt for the 318-340 is said to be a 3/8-16 and it is actually 5/16-18.

I was with my Dad in his grouchy old age when he and my son were building a 340 for the boy. When it came time to bolt the rocker shaft down, Dad told Cody to torque them to 30 ft-lbs per the service manual. I thought at the time that was way too much, but you didn't argue with Pop. Cody torqued them to 30 ft-lbs and one went 'snap'.

Dad said to Cody, "Now you've f**k'd up!" Probably thinking that the boy had use more torque than 30, Pop was pissed.

So we went over the service manual and I showed Pop the torque references and we pulled all the bolts. On some you could actually see the stretched threads. We replaced them all and torqued them to 200 in-lbs. No problem'o.
 
73 FSM has SB @ 5/16x18 200 inch lb, BB @ 3/8x16 25 foot lb
Over torque could also deform rocker shaft.
 
My 67 FSM (for A100) shows the rocker shaft bolt for the 318 being a 3/8-16 @ 15 ft.-lbs. Almost every spec for a 5/16-18 shows 15 ft.-lbs. (or 200 in.-lbs.) Except for the "intake manifold bolt" of 270 in.-lbs. (or 22.5 ft.-lbs.) must have been a Monday or Friday for the proof reader
 
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