Yeah 24 ft lbs except for the two out most nuts they're 23 ft lbs. I beleive it's something to do with them being nuts on studs, but it's stupid. 1 ft lbs for that size of a bolt going into cast iron So I just torqued them all at 24 ft lbs. As far as the tightening pattern, snug everything up(finger tight) then start in the middle & work your way outward. BTW if you're ever in question and don't have the time or resources that goes with most anything unless there are engineering mistakes. Start in the middle and work your way outward.
I just installed my intake/exhaust on my '87 Renix tonight and IIRC when I looked the book I noticed the H.O. bolt pattern. It was the the center bolt towards the rear on the bottom as #1, then the center bolt towards to the front on the bottom as #2. Then the center bolt on top as #3, then possibly the next centered bolts on the bottom, followed by their corresponding top bolts, then the bottom outside. Again, it is different that the Renix but I did take a look at the H.O. models and I think thats correct.
I ended up getting to use a torque wrench but it took a lot of combination of extensions and stuff, lol. It really sucked
And every time you add an extension or swivel, the torque value changed/reduced.
I just tighten them up in 3 "pulls". Seat all the fasteners kinda hand tight in the first sequence. Start snugging them down in the second sequence. And put a good final tighten on them in the last sequence.