As far as I know, the only difference on the timing chains is that the older engines require a provision for the mechanical fuel pump eccentric. Aside from this, they are interchangeable. OEM style gears are phenolic to reduce sound.

Does the cam turn easily?

Where are you? If you are gonna dump a brand new engine, I will gladly remove it for you.

 

Not sure/can't recall, but where is the thrust bearing located in the SBF?

Bet that's different than the SBC. Several posts in the past have mentioned a Chevalay guy putting the thrust bearing in the wrong place. Seems far fetched, but thought I'd throw it at the wall and see if it sticks.....

 

Well, I loosened all the rod caps to about 5-8 Lbs.

(with the timing chain off) I found the tight spot at 11 o'clock motor upside down to start to turn at 98 Lbs when the torque wrench click went away.

The easy spot was at 3 o'clock and turned at 72 Lbs.

I found a Bronco site that said 75 Lbs is about right for new rings, (no lifters heads, timing chain or plugs), then after about 2 hrs of break in it goes down to 50 Lbs to turn.

I'm not too worried about the tight spot 98 Lbs is just what the crank needs to initially overcome a rough area in the cylinder is what I'm thinking

The cam turns nice and smooth by hand.

What we did find is the bottom timing gear was roughly 3/8 away from the crank so that could cause some chain binding. We suspect the Harmonic balancer wasn't on all the way to force the chain drive gear all the way back to the crank mating surface. We are cleaning the HB center hole with a wire brush then do a test fit to see if it positions the chain crank gear better.

Here is a picture of rod bearings at cylinder 3 and 7. Not too bad so we decided to not change them. This is the worse wear the others bearings were better.

 

Well we solved it. We found a couple of things,

The biggest thing was the Harmonic Balancer got stuck on the crank and didn't go all the way in. It caused a nearly 3/8 gap between the crank and lower timing chain gear which put a bind on the chain. The torque wrench said we were turning the crank at about 120+ Lbs. We cleaned up the Harmonic Balancer of some rust and gunk in the Woodruf keyway and torqued it it back on.

This time the Harmonic Balancer pushed the lower timing gear all the way back on the crank. We guessed we had about .012 to .025 gap at the gear an crank this time. We didnt notice the 3/8 gap the first time.

We lubed the hell out of the cylinders both top and bottom and turned the engine over about 40-50 times by hand. This helped smooth out the rough spot in #2 cylinder.

After re-installing the Harmonic Balancer and timing chain, the Torque at the crank remained looser at about 75 Lbs all the way around.

We got her all buttoned up ready for a first start, and she took off wide open and roared like a monster with open collectors. But now we can't achieve an Idle. My mechanic guy thinks its a vacuum leak at the manifold gaskets since the Rogers Heads have been shaved .010 at least once that we know of, or a secondary butterfly adjustment in the Edlbrock 1405. but thats a different thread.

Some additional things that helped start the beast. We got a new starter the old one was 20 years old and had loose bearings. the starting battery was weak we added a second battery in parallel.

One thing to remember, disconnect the batt wire from the coil when she starts as an emergency stop and make sure its not reconnected after the engine is shut down. We fried a set of points and my $45 Pertonix flamethrower coil. Rats.

I hope this helps someone in the future

 

Cool. You will be tweaking it for a while until it settles into its happy spot.

I didnt realize the damper helped position the crack sprocket. I positioned mine by eyeing it in and left it like that. Seems to work.