Timing tips

Map63Vette said
I've got the cam card here. The short version is 267/275 intake/exhaust duration and 0.549/0.536 lift intake/exhaust. LSA is 110 as it turns out. It says 4 degrees of advance ground in. 106 intake centerline and 114 exhaust.

In at 106 the rest of your cam events look like;
267 intake/120.5 compression(Ica of 59.5)/108.5extraction/275exhaust/51* overlap
FYI
I ran a FTHcam in my alloy-headed, 11/1, 367LA(6-liters), very much like that;
270 intake / 119 compression (Ica of 61)/ 108 extraction / 276 exhaust/ 53* overlap
I have run three cams in this engine..... so far; and this one, by far,was my favorite. @3650 pounds, car went 106 with that combo, first time out. She had enough power to spin the 245s tires thru two gears at least; usually to 60mph or more. I very quickly fit 295s back there, then 325s.
With his engine, I ran a Mopar A833od with a GVod/splitter behind it and 3.55s. The ratios were
3.09-2.41-1.67-1.30-1.00-.78-.55....... splits in red. Yeah, I know, seven useable ratios with nice splits. With this gear combo, 65mph was; 2870 in direct/2240 in GVod/1590 in double od.
Here comes the point;
It got no better fuel economy at 1590 than at 2240. Engine vacuum was higher at 2240, and I could get the timing closer to what it wanted; which was over 56degrees for cruising. The Distributor kicked in 45 degrees and my dial-back could add back, up to 15, for a total of up to 60.
But; with a manual trans and a starter gear of 3.09 x 3.55=10.97, the slowest I could drive with 14* idle-timing, was about 5.1 mph, before the engine started bucking. This is too fast to walk beside. I found that by retarding the timing to about 5*, the engine could maintain 500 rpm pulling it self along at 3.6 mph, which is what I needed. So that means, from 14, I needed to set the Dial back to 9retard leaving just 6 for advance. Therefore my cruise timing would have to be 45+6=51, close enough.
After I figured out that I more or less had a useless seventh gear, I installed 4.30s to cruise at 65=1930 in Seventh/ double overdrive. This gave me a starter in which 550 was 3.3mph. I was able to swap 3 degrees from retard to advance, and now ran 45+9=54* @1930rpm.
All this to say;
1) I know nothing about hemi's
2) I know a lot about tuning my 11/1 alloy headed 367LA. I have run 3 different cams in it.
2a) I know with a manual trans, mine does not like a lot of idle-timing down real low, but
2b) by 2800 it likes at least 28* for power, and
2c) is satisfied with 32/34 at WOT, and I delay it to ~3400 to keep it out of detonation on 87E10,
2d) and it likes a chitload of cruise-timing; at least 56*. My vacuum advance is set up to pull in 22*, and while it's enough, the engine really wants and responds well to in the range of 56 to 60 degrees@ about 2240 rpm.
BTW-1;
I no longer run this combo. The cam died. And I came to the realization that 7 useable gears in a streeter was about two too many. I now run a cam one size bigger. And she is back to 3.55s/ but now a Commando trans(3.09low), still with the Gvod, and turns 65= 2240
BTW-2;
I ran/still run 87E10 full-time in this 11/1 367 with alloy heads, with no sign of detonation ever and, I took it apart 5 winters in a row looking for it. Pressure was 185 with the smaller cam, now ~178.
BTW-3;
looking at this;
In at 106 the rest of your cam events look like;
267 intake/120.5 compression(Ica of 59.5)/108.5extraction/275exhaust/51* overlap
There is nothing that I can at all see problematic in terms of tuning it.
BTW-4;
If your dual throttle bodies are NOT progressively staged;
I'm pretty sure your cruise problem is gonna eventually trace down to that. The cam you have wisely chosen, when coupled with high cylinder pressure, is very powerful down at cruise rpm, and wants only a tiny amount of throttle opening at ~2200 rpm. I was able to squeeze 32mpgs out of mine on a certain test-run. I used an adjustable, over-rideable, throttle-stop to help me keep a steady foot, on the primaries of a Holley 600 no less, just to control the throttle opening exactly..
With EFI, if the throttle opening wavers at all, your AFR is gonna jump around in lock-step with the wavering throttles. No amount of timing shenanigans can deal with that. So, it is my hope that your TBs are staged.
BTW-5
that cam, with a manual trans, in my 367, liked an idle speed of at least 650/700 was better. And it liked in the neighborhood of 24* at idle. Obviously, with a carburator, and a manual trans, that would be a disaster. I compromised at 12/14 degrees@700; but down at 550, I had to cut her back to 5* to prevent bucking; because the AFR with a carb is hard to control down there and at 550@14* the engine is already making too much power to accurately control, she is chomping at the bit, eager to be pulling. I had to hobble her a bit.

Ok so, hope this helps, and
Happy HotRodding.