well now that everybody has had a few minutes to simmer down a bit, i'll at least give a bit of a longer term update on it.
again no solid dyno numbers to show, and probly never will.
Seat of the pants feel is a significant gain in torque no doubt, but this is also in combination with a proper tune in it compared to stock programing.
On a familiar route, loaded with 6000lb trailer, and other goods, flat ish road, cruising at 100km per hour, (thats a hair over 60mph) with the previous stock 5.3 setup, it would be in and out of 5th gear, at 2200ish rpm, downshifting to 4th to keep pace with traffic.
now on that same trip, it can stay comfortably at the 100-105km per hour road speed at that same rpm and not be downshifting to stay at speed with slight inclinations and traffic fluctuations, and will handle it without downshifting, unless I get significantly farther in the throttle to increase speed.
however i can tell you that this setup needs good fuel!!! 91 minimum, I have still been getting a bit of detonation on that during low engine speed, high load situations, 94octane would be the ideal fuel to run for sure!
Hindsight, and my tuner told me this right from the get go, would have been best to use a 317 head, rather than the 243/799, just to drop the compression ratio a bit.
And also, more then likely it will get a bigger cam with more lift and removing the VVT as was suggested previously, just cause i can't leave **** alone...

 

Anyone who suggests the 317s over the 243/799s for NA is a moron. You simply lose to much compression.

 

when you say too much compression, can you elaborate.
I understand where your coming from for an NA build that more compression ratio is good.
but with todays **** fuel that you get out of the pumps, the drop in compression ratio would be negligible on actual overall power output is my understanding. vs having it detonating on anything less then 91 or 94 fuel?
any estimation on what compression ratio's these 243's would have on a stock bottom end l96 vs. the 317's?
looking for suggestions for real world daily driving, not hero power numbers to bench race with, thats originally why i felt i would post up the project i have on the go with this setup.

thanks everybody for bringing your experience to the table here, I don't mind the criticism.

 

I daily a 370/706 combo with 93 octane. It runs about 12-12.5:1 compression. I’ve run it this way for over 2 years.

As long as the tune is good, there shouldn’t be an issue. I get great fuel mileage and have tons of pull down low.

317s are 71.06cc. 243/799s are 64cc or 65cc depending on who’s answering.

With the loss of compression, you also lose air velocity, which means less power.

706 heads are better than the 243/799 up to almost 6000rpm.

Food for thought.

 

phew 12.5 :1 thats up there for a daily!
without having measured the cc's and whatnot before installation, i can only assume that i essentially have an ls2 type setup rated at 10.9ish.
I understand the air velocity point, thats why i chose this setup with the cathedral heads, rather then the l92/ 823 rectangle port head. but i wasn't expecting to see this much low speed detonation.
i would care to guess that your setup would never see the type of driving scenarios that mine would with a 3.90 rear, higher stall convertor and larger cam, bleeding off low speed dynamic compression, compared to my stock stall convertor, 3.42 rear gear, and towing a trailer primarily, at lower engine speeds,
i only have a basic understanding of this, so don't for a second believe that i know what i'm talking about, i'm only doing my research on the matter.
can i post up the tune file from my tuner for everybody to have a look at as well as a log file, or is that frowned upon?

 

Post away.

I can get detonation if I command too much timing but I’ll back off a couple of degrees until it stops.

I pulled 5200lbs up I26 in Asheville a few weeks ago. Those are 6% grades. I was in 2nd with the converter locked at 50mph and it pulled fine.

Engine ran up to about 190 and the Trans was less than that.

 

yep 6 percent grade is up there thats for sure.
not sure what that highway is like, but for example i travel the coquihalla highway number 5 in BC somewhat often with the trailer behind, as in the tv show highway to hell on discovery, that can put the hurtin on transmissions if your not carefull... starting with 4percent grade for somewhere around 20km and slowly increasing to finally a 5km long 8 percent grade to the peak summit!
have a look at the attached tune file and the log file of an unloaded drive to work in the morning.

thanks for looking at it everybody!

 

heres a log from this weekend,
loaded, high ambient temps, steep grade, 1000meters elevation climb (around 3,000 feet)
trans temp stayed about as high as i would like to see it, engine temp climbed up there into the 225 range,(still running stock temp t-stat).
this was on a tank of 89octane fuel.
any thoughts on how this looks?

 

Did you ever fix the detonation? How thick of a head gasket did you use? Would a .060 compressed thickness gasket lower compression enough to get rid of detonation? And did you ever install a bigger cam and eliminate vvt?

 

I did yes, all of the above, mostly...
put the bigger comp cam xr269hr in there, vvt gone.
just a stock mahle replacement head gasket in it.
have also been playing with the timing tables off and on over the last year and a bit. have been getting better with it. pretty much dumped a whole bunch or timing out of it in the high load areas, got it much better now, still gives a little tickle every now and then when its real hot and I know there is some bit of 89ish or lower mix in it, i usually throw 91 in it for when I'm towing.
otherwise I happy with it overall. I believe i managed to pull off what i was intending to do, low budget, moderate boost in performance, nobody can really tell the difference from stock, other than a bit of chop to the exhaust, which some people notice.
could I have done it differently? sure
should have done a 6.2? sure, but those are ******* expensive to get up here...
should have done a blower? sure, again way over my budget...
should have bought at diesel truck? as stated, i don't tow that much weight, my 1500 is adequate, paid off, and i take very good care of it, so no i'm not buying a new pickup...