I finally got this 950 ProForm off my buddies car. So I plan to go through it and do some jetting and try it on my car at a T & T on Oct 29th at Cecil. I will start with jetting close to what I have in my 850. May not run any faster but what the heck I have the carb so why not try it. Ron

Heck yeah! Curious to see what it does!

Your 850 Holley and that Proform "950" probably need significantly different jetting. Find out what the Proform has in it first before jumping in ready to put big(ger) brass in it.

i bet this is the baseline for that carb
https://www.proformparts.com/common/instructions/67202_specs.pdf

https://www.proformparts.com/product-exe...category_id/181

Call me cos I have proven tunes for those...............760-900-3895.............

Hopefully you have weather data the last time out with the 850? And a weather station to collect it at TnT with the 950???

At the minimum, just density altitude will suffice to help quantify any gains/losses.

good luck Ron

Tex

Ours ran best on the 512 with 92's in all jets and #28's for high speed bleeds.

Thanks for the replies. I actually put this carb on his Mustang about 5 years ago and as far as I remember it has the stock jetting. Thanks as I may call you Thumperdart as I will pull the bowls and make sure of the jetting but I want to try and have it close for my car and I have not used a ProForm so I am not sure if it needs to be jetted close to what my 850 had as I am not sure yet if it has around the same air bleed sizes as the Holley has until I check them. I dont think I will get a chance to mess with it until Monday or Tuesday this coming week. I plan to get it on the car and get it close to what I want for the track and then I will take my 850 with me to the track in case I want to bolt it back on to compare. Course if it runs faster then it has before I am sure I will leave the 950 on the car. Ron

It will be interesting to see if the carb swap makes a differance, being the 950 has a smaller venturi then your 850 and flows less.

Hopefully it goes a little quicker.

Always nice to get a new "best".

Holley makes a bunch of different "950" carbs. XP, classic HP, Street HP. They vary in size, most of the newer ones are larger in Venturi size than an 850. It depends on which one your hands are on.

It's a ProForm, not a Holley. I'm going to guess 1.40-1.45" on the venturi.

The throttle response may be a little snappier but on a 493 I doubt the 850 is sluggish. IMO it won't be any faster as it is actually a smaller carb unless the venturi is bigger than 1.56".

Proform venturi size is 1.45 and the older Holley 850 should be 1.56. I have a Prosystems 950 for my 505 and am debating getting a 1000 main body for it, so I will be interested in the results.

Like damn near EVERY newer carb out there, it need more than just a jet change. The ifr`s need to be lowered, emulsion calmed down in terms of TOO MANY holes, t-slot jets, different idle and hi bleeds etc. Run it then call me and I can either do those things for you or help ya do em..........

Thats true but I was surprised how well this Holley 850 DP works on my car with very little done to it. Course the only jets it has is the main jets but other then changing the jets and P/V's and drilling the pump nozzles I have not done much to it. And that because it works really great on my car for driveability and how well it runs. It may be a tad fat on the IFR but not that bad as I leave the same plugs in it all summer as the ones in it now have been in there about 6 months. I really like how nice this 850 works on my car and unless this carb goes faster which I am not sure it will I will most likely put the 850 back on. But I do like that this carb is much more tuneable then the 850 without drilling and tapping or changing the 850 metering blocks. Ron

Well I put it on my car as I got some free time yesterday and felt up to putting it on. The Proform had the stock jetting of 78 and 86's and I jetted it the same as I had in the 850 for now as I had forgot I jetted the 850 down as I had gone to rich at one point. It had 83's and 91's in it with a 3.5 P/V. The Proform now has 83's and 91's in it with a 4.5 P/V. I remember I had jetted the primary down a tad on the 850 to clean it up while cruising some. But I tell you this Proform so far runs great ! After I adjusted it I got a nice clean idle with great throttle response. So far I am very happy with it as driving around it runs and feels as good as the 850 did. In about a week and a half I hope to see how it works at the track. Ron

Been saying for years that you need a bigger carb and a 1050 dommy could shine even more.............You hittin the track soon......

When we go to the track for TNT, we bring probably 3-4 carburetors and try a bunch of stuff.....When you have time its a great way to try things. Loaned all mine out this past week and have only the SV1 to play with...

You loaned out the 1250.........

I did....and he wrecked the needles and seats. The gauge went bad on it, and he set fuel pressure at 15psi, and the gauge read only 5lbs.....How do you like that. Never made it out of his garage. Now I have to buy a new set, again...

Check out BLP's billet main bodies, for less than $300 you get several choices of venturi sizes and boosters.

1.59" BLP billet and 1.40" aluminum form my Bigs 950HP.

How are the N&S`s wrecked? Just clean em up and go..........

What is you technique for getting a dent out of the needle?

Dent? I do see a wear mark even on new ones but nothing too horrible...............

Not seeing how high fuel pressure would "dent" a needle to begin with. High fuel pressure is simply going to lift the needle off the seat and overfill the bowl, usually blowing fuel out the vent tube. It isn't going to apply any more force to try to seat the needle and damage the taper. Only time I've ever seen needle damage is when someone doesn't use the proper method to set float drop and forces the needle into the seat.

Ron: Why do you insist on trying to duplicate your Holley 850 tune in the Proform carb? They have different venturi sizes (1.56 vs 1.45), different boosters (std downleg vs stepped), very likely different PVCR sizes, different metering blocks... NOT the same in many key aspects.

Not the proper way in my eyes either..........

Here's what I'd do for better baseline to try it without modifying someone else's carb:

- Temp in 80s or 90s, use 78/86 jets; temp in 60s or 70s, use 80/88
- Change emulsion to #1 & #3 open (supposed to be pre-drilled .028", but they're not always drilled consistently), #2 & #4 plugged
- Leave the standard .055" PVCR in the primary, run a 4.5 PV, block the secondary
- Use .035" IFRs and leave them in the raised position since it's not your carb to modify
- Use .035" squirter nozzles primary & secondary

Although the Proform is a smaller carb in pure airflow potential than your current 850 ('cuz of the different venturi size), it could show gains in both the 60-ft and 1/4 ET & MPH because it's more responsive AND has better shift recovery than the 850. But you'll only know by testing...

Believe me guys its not that I insist on trying this its the fact I got my hands on this carb for free. I live on disability as I have for a few years now and money is not something I have much of as that why basically my 63 has stayed the same from 2011 when I put the 493 in it until now. I just dont have much spare cash to play around much with my car. I am just happy to at least be able to gas it up and cruise in it and hopefully go to a test and tune in a week or so. Money is the reason I have not raced in almost two years and the fact it still has an 8-3/4 in it. This carb at least does not have any choke airhorn that my 850 does. Sure I can make changes to this in any of the jets I like as my buddy wont mind that at all. Its running awesome buy the seat of the pants meter but we all know that means nothing until I see how it runs at the track. I hope maybe it will 60 better and pick up a little as thats about all I can do for now. I wish I had the money to buy some main bodies and make some changes to it as I like the fact this carb has much more I can tune on it without drilling. Yea it may not go any faster with this as I will take my 850 with me in case I want to bolt it back on but hey at least I will get to make a few passes again and you know I am going to love that. Ron

I understand the $$$ factor and its impact. All the money I've received for selling some parts recently is going straight to paying down unplanned car repairs & medical expenses not covered by my insurance.

Since I'm only about 1.5 hrs southwest of you (I can drive to Cecil County in 2 hours), if you can hang onto the Proform long enough to get to another T&T this fall, you can send it to me and I'd redo the baseline settings like I suggested above for you to try again. The only thing I might not have here would be the squirter nozzles, but could drill out some spare .031s if necessary.

I have all the parts on hand to build something comparable for myself. It would be interesting to see how it works, even though I'd want something a little bigger if it was my car.

I've been reading the threads about metering block tuning and emulsion over on the Bullet and some LS sites and now my head hurts from brain expansion I know this is some basic information but it seems complicated until I can start to see a difference with an AFR meter.
Thanks for starting this thread Ron I could use some good information because I know my carb needs some fine tuning for street cruising. I know I can make it perfect with the Quickfuel blocks and Pro-form 1050 body.
Time for a cold beer to cool my brain down from all the tech I have absorbed in the last 2 hours.

Gus

I am happy with how I have it set right now. I have all the carb drills if I would want to drill the squirters any as I had drilled the ones on my 850 but it has great throttle response right now so I will leave them alone for now. I dont have an 02 sensor or AFR meter as I am still old school alot since I have tuned the old way all my life reading plugs and by how I feel the carb is working. I agree the 02 setup is great and maybe one day I will get one on my 63 but not right now. If the weather holds I will at least get a few passes in and see how it goes in about a week. Ron

Ron - Did you get to "Weasel Bounty" to try out the carb?

Yes, eenquiring minds wanna know!

Yes I did get to the track and did not have a good day. My joints were hurting alot yesterday from being on my feet so much on Saturday as thats why I did not post yesterday as I just wanted to lay down off my feet. It just tears me up on my feet alot with all my joint , back and knee problems. Both of my sons went as did I as Ron Jr took his 400 Dart and Tim my youngest took Ron Jrs SRT-4 Neon and drove it.
As for me one thing I kinda forgot was my slicks have been on my car over 3 years and they are about shot as it did not hook good other then one pass. The first pass with the 950 was my first of the day and it did spin a good bit and only had a 1.62 sixty foot as it ran a 10.93 @ 123.15. I felt the mph was down some from what the 850 usually pulled. And I knew I would not get alot of runs in as it got very crowded. So I decided to bolt the 850 back on and make a pass to compare the mph. I ran the right lane this time as my first pass was the left lane. Well it actually hooked good with a 1.52 sixty and felt like a great pass until I hit third gear as it layed over as soon as I hit third and then picked back up in the traps. Ran a crappy 10.91 @ 122. Well I knew I had turned the 850 upside down to drain the gass out of it so I could put it in a box in my trunk to bring with me and I felt maybe a little dirt or junk got in it as it has never done that before. The staging lanes were packed so I jumped back in the lanes hoping to get another pass in. Then we had about a 1 hr cleanup from someone who oiled the track down. I finally got a pass in as it spun some and had a 1.55 sixty and it did not lay over this time and felt pretty good but it only ran a 10.89 @ 123.87. When I hook good at this track it will sixty ft in the low 1.50's all the time with a 1.50 best. It felt fine the last pass but I thought it would have been in the 10.70's as I usually run 10.70's at 124 and change at this track on what I thought was worst days. But I did find out the 950 pulled about the same mph as the 850 did. I really thought it would have run a good tenth or so better then the last pass of 10.89 but at least I did not break anything and I drove the 90 mile round trip with no problems as did both of my sons who also took their cars. Ron Jr ran his best ever of 11.41 @ 117 as his best had been 11.45 and the SRT ran 14.30 best as its stock with just a tuner on it. We did not have time to mess with the SRT-4 but we may play with it at a later time. I wish I had had more time to put the 950 back on and make some changes on it but I feel it would have run at least a low 10.80 if it had hooked with the 950 since it only had a 1.62 sixty I feel I lost at least a tenth in the 1/4 on that pass. Bottom line is the 950 might be a tad quicker but it did not mph any better as I dont feel its much if any faster with the 950 right now the way I have it set up. I mean it ran good and drove good with the 950 but for now I will give it back to my buddy and leave the 850 on it as I want to try some other changes down the road. First I need new slicks and I really want to get the MP 337 intake and try it with a Dominator if it will fit under my hood and if not I still hope to try it with the 850. I will say I was not real happy as it seemed like a nice day and I thought that with the 850 it would have run as good as before and at least hit 10.70's. We did seal the scoop on my sons Dart which it never had before so that may have helped him hit a new best of 11.41. His car ran in the 11.40's all day on all 4 passes he made. At least nothing broke and I drove it home and at least ran a 10.89 on a bad day. It could have been worse but I was hoping for a little more. And as they say................thats drag racing.
Here are a couple pics I got as I did not have a chance to get any action pics. The first is at Double-T Diner as we met a friend there and the last are in the staging lanes. Ron

Jrs Dart.

I also wanted to say even though I did not have the best of days with my car I had an awesome day racing with my kids and it was fun to see Jr smiling from ear to ear since his Dart ran good all day. Ron

Glad you got out Ron! Sorry it didn't turn out like you hoped, but any day you get to go to the track and don't break anything, thats a good day.