I just picked-up another Pro-Systems 1000hp 4150 after discovering that my new 414 loves the original calibration of my old 508 P-S carb. The 830 worked pretty well...or at least I thought until I swapped the P-S on it and then it was like The calibrations of both were very close (the new one just has slightly a fatter PVCR and needle/seat orifice as well as drilled butterflies). I forwarded the build specs of the one I bought (second hand but still new in the box) and sent the motor specs to Patrick last night.

This morning he said the new carb I picked up was pretty-much a perfect choice and to just jet up the mains 2 numbers in both plates. Can't wait to

Can't beat Pro-Systems for Fast Response and no BS advice!

Has Patrick upgraded the 4150 components in any way since you purchased your first one?

I had never used Pro Systems before,but after getting my hands on an SV1 for some dyno testing a while back,I was very impressed with him.
I called him to ask him a couple of questions about it and he offered up his cell phone number in case he was out of the shop in the event that I needed any help.I would highly recommend him for anybody that wants the best in customer service.
Keith

Brad,

I bought the first one in 2003 and the components are the original style Holley. Both old and new carbs have the 4500 metering blocks and screw in bleeds. This new one has the modern zinc finish and the updated float bowls with the larger (snap ring retained) sight glass and a (Red) billet Base plate. The only thing I don't care for with the new vs old is the plastic Acc pump lever arms.

I wouldn't sell my original one for $200 more than I paid back in 2003, by far the best and most responsive carb I've ever had (and that includes, Webers, Predators and lots of Dommy's)

Pic of new carb:

although I don't run his stuff any more Patricks customer service is second to none!
I even got to race him a few years ago at the Snowbirds. Sent him back to MI!!

What's the venturi diameter? Is that just an OOB 1000 HP 1.56" main body? It doesn't appear that the venturis have been machined in any way.

Well the 414 really likes the old 1000hp (anybody running one on their 408-416 combos?) and the new carb dropped on the 517 is just slightly stronger than the old one, I had suspected it was just a tad lean through the middle to top before but now it rolls-on to full throttle even stronger now.

I never had any sort of idle issues with the old 1000HP carb on the 517, the new one has drilled butterflies and a bit larger needle/seats in both bowls so it wants to idle about 60-80 rpm higher in park (around 1100 vs 1050) even with the idle screw all the way out.

The older P-S 1000hp set back to the original jetting of my old 508 which was about 610hp looks to be dead-nuts on for the 414. I had to mod my 2" 4 hole HVH to fit a power brake booster orifice, I haven't layed a Vac gauge on it yet but I've got to say the idle is stronger and smoother that I ever thought it would be with a 266/269@.050 and 107 center solid roller (Cam Motion mid 90's IROC Avenger) grind. I think it idles better with the 1000hp than it did with the 830.

Again, I can't thank Patrick enough for the great advice and customer service!!

517 with her new "lungs"