I wish I knew that last week. I did use UPS to ship.  Thanks gentlemen!. I will try FedEx next time!.....John

Tough question on value.  I would say buying an RPM and keeping the Sidewinder, I wouldn't bother

However, with the potential value of a Sidewinder, you may get a little power and some cash to boot.  Depends on the buyer. 

But then you lose a unique manifold

That being said, I do not expect it to be magically different, but I would expect it to be a little more balanced and probably make a bit more at the peaks.

Awesome, any chance you have access to a dyno to give it a spin?

I just had to pay tariffs on a jerico trans and clutch system and holley carb shipped to illinois that landed yesterday. Everything was made in the usa. I am not arguing here, just saying....John

And yes, that is why I told the customer I would not use a metering block.

For the gentlemans sake since he's spent some money on his carb, and would like for him to be able to use the carb, (or anyone else who has who either has a 950 or 1050 cfm 3 barrel and wants to run them,) and as long as his carb has the correct primary metering plate #5615, if it hasn't had the PVCR modified yet, that would mean the PVCR are currently at .040" which will cause primary tuning issues, such as a bog, then he'll up the jets then it will run pig rich, he will need to open the PVCRs up to .070" the same as the 850 DP which come with .070" PVCRs, which basicly what the primary side of the 3 barrel is.

Basically, with the corrected PVCR you would tune the primary side of a 3 barrel holley the same as you would a 850 DP.

In 66-67 when these carbs came back out, they were tuned for smog, thats why the .040" PVCRs. The 1st 3 barrels came out in 64, Chrysler had the them made for the Nascar HEMI, I don't know if they were 950 cfm or 1050 cfm I've never seen one so don't know what size they were, but had no unusual tuning issues, the primary metering blocks on those were #4328, and I have one I picked up off Ebay and those have a .093" PVCR, the larger PVCRs were needed due to the restriction caused by the emulsion tubes in the main well reducing fuel flow, which I am able to see the end thru the channel restriction.

1st pic is of a 5615 metering block, with a .040"pvcr.
2nd pic is of a 4328 metering block, with a .093"pvcr