Well today was the maiden voyage. Set the timing, and idle, and gave it a few blips of the throttle. It doesn't like 8 degrees with the 10:1 CR, and I could hear it ping, even in neutral. Backed it off 4 degrees and it sounded fine. Drove it around awhile and it seemed to perform well, but a bit rich at idle. Got home and turned the idle mixture screws in until it started to stumble a bit, then backed them out to smooth it up. These carbs have the new preset floats without external adjustment. I'm contemplating swapping the bowls from the 450's over to these carbs, but will give them a chance first to see if I'm OK with them. Seems like a cop out on Holley's part, and I like the old float adj. better, but really never change the setting once they're set.
I reduced my fuel pressure a bit also, as it had crept up to 5.5 lbs. and I like 4.5 lbs. better. Supposed to be nice for the next week, so I'll give it a few test runs, and gradually work my way farther from home. Hate to go too far until I know I don't have any bugs to work out!

This the final setup I built to support return springs and fuel lines. Much smaller than my original plan, yet seems plenty sturdy. Just flat aluminum bar tapered to look better, and a one hole strap around the line:


You can see the same material at the back carb bolt bent down to attach the return spring. Surprising how much lighter the throttle pedal is without the bell crank in the system.

 

Looking good.

 

Thanks Bill. Made a couple runs, but still sorting out the idle on the carbs.

 

I got the tune spot on today! Had to pull the carbs to access the secondary throttle plate setscrews, and turn them in a bit to open the secondaries slightly. After putting the carbs back on and firing the engine, the rpm was higher, and I lowered the idle screw position to bring it back down, and it idled great! No dying, or stalling anymore. My thought is that the two 600 cfm carbs needed the primaries open slightly more to not stall out from lack of air at idle, which caused a rich mix, and also a higher idle rpm to keep from dying. By opening the static position of the secondary plates it allowed air in and I could then turn down the idle speed and not completely cut off air at idle. I'm not a carb guru, or tuning genius, so this is just my guess, but it is working, and working well!
I also put a restriction in the idle circuit to lean the carbs out. Cut some pieces of #14 awg solid wire and put them into the idle passage on the back side of the metering block. They're loose enough to allow fuel pass, but restricts the amount enough to really clean up the rich idle!
I put my vacuum gauge on while setting the idle mixture screws, and it's got a good 15" of vacuum at idle! That really helps the low end response, and I could probably go back to my power brake booster now if I want to. I removed it with the last cam for lack of vacuum to work the booster.
Now I can get some seat time and get the rest the engine broke in!

 

Sweet!

 

Thanks Dalton! It's really been testing my patience the last 3-4 days! I'm not a carb guru, so trying to figure this out and get it tuned has tested my knowledge! I was getting near the end of my bag of tricks and wondering if I'd get it running smoothly!

 

gonna have to take it to cars and coffee on a Saturday and show those ricers a thing or two. lol

 

I thought it was just out my way that Cars and Coffee was all ricer cars? Same thing out your way too I assume?

 

no the one in Tigard is full of high end stuff like lambo's, Ferrari's, audi's, etc

 

Well the Austin is on hold for awhile. Although it runs out well, it begins to load up at idle still, and eventually after a long cruise on the freeway it fouled out the plugs, and loaded up at idle. Stock jets are #66, so I've ordered two sets in #62 and #58. I'll probably jump right down to the #58 and then watch plug color to see if that's too lean.
Thought I had the tune working, as around town it seemed good, but after the freeway run it showed the plugs were sooty and not running lean enough. Should be here later this week, and then I can get some more tuning done.