Yesterday I converted my Holley 80457 to a 4150 with a rear metering block and added a quick change secondary top. Now after I get the car broken in I can dial it it in properly. It was pretty simple to do, I got the cathedral bowls off a junk Holley I bought off ebay, the secondary kit was from Quick Fuel, I also added a heat dissipator under the carb while I had it off.

 

After I got the carb back on I bent up a set of hard lines for, I thought it would look cool to try and duplicate a factory look to the fuel lines, I thought the copper plated steel lines kind of copyed the look of the tri-power set ups. It was pretty easy to do I got all the parts from the local hydraulic shop.

 

Lookin' good. What primary/secondary jets did you use? What size pump discharge nozzle did you use? Have you had a chance to fine tune it?

I got a 4150 and am looking for some performance ideas for my 350.

d1

 

Wow, looks great. Nice job on the lines, too.
It'll be interesting to see if you notice a performance difference.

 

I used 65 primaries, 69 secondaries, and a .31 discharge nozzle. After I get this engine broken in I'm going to run it over to the shop and have them run it on the dyno to get the jetting and spring rate on the secondaries dialed in.

 

Cool, please post dyno results when you can.

d1

 

I've done the same thing on a 396 BBC, with excellent results!
Few recomendations, though;
Get the fuel line away from the heater hose,
I used the black spring in the secondaries,
the white eccentric for the bigger accelerator pump,
2 steps up on the pump squirter
I was at 68 primary and 88 secondary - plugs were perfect!
Went 13:53 @ 109.88 w/T-400, 3:55's + stock converter, in a 2-dr wagon!
Also had a torquer manifold with a 1" spacer.