I recommend getting the Standard Motor Products kit p/n 361D. RockAuto has it for $19.75 using the 5% discount code you can find on the web.
The Standard Motor Products (Hygrade) kit, Mike's kit, the $50 "High Grade" kits on eBay, Etc. Etc. are ALL rebranded Walker Product parts in one form or another. What I mean by that is the Ebay kits are dumped out of SMP (Hygrade) boxes with $20 markup. SMP purchases individual components from Walker and makes up their own kits. Yes, I've verified this with SMP.
Thanks for the recommendation on the rebuild kit. It looks decent. I'm going to pick one up. It looks like a power valve is included in the kit. Would you happen to know what size?
The Fel-Pro 1901 mounting gaskets are not concours correct by any means, but are extra thick and seal.
I'll give this gasket a shot.
A big cause of "stumbles" I have found are from primary jetting too low. For example on the C5ZF-C the #49 primary jets do not cut it with modern fuel and a mild cam (262/270 duration). You really need to be at #50 minimum or #51. It is even more of a problem if you're running the generic 7.5 Hg. power valves from the rebuild kits. Ford used a stock 8.5 Hg power valve (on the '65 1.08 and 1.12 HiPo) that came in sooner (when vacuum drops to 8.5 Hg, versus 7.5 Hg). I was buying 8.5 Hg. power valves from Quadrajetparts, but they phased out the kind that I liked that fit well (snout had good clearance in hole) and now they appear to just be selling the Holley brand with snout that cuts it damn close to hole wall.
Now we're talking, just the sort of info I was looking for. The carburetor currently installed is a C5ZF-D. Primary jets are #49. Secondary jets are #58. I'll pick up a couple of #50 and #51 primary jets and a 8.5 Hg power valve if not the size included in the SMP rebuild kit. Do you think the #58 jets are good for the secondary jets? I have a pair of #59 secondary jets I can install if need be.
I have a really mild Comp Cam P/N 31-215-2 installed in the engine. The duration is 252/252 The full specs for the installed cam are in the attached picture. Let me know if you think this cam would change anything with respect to the jetting you mentioned above.
As far as what runs best...
The C5ZF-C, Change Level C (5EC dated) I'm selling was the best running 64/65 1.08 out of about twelve C5ZF-C/-E carbs I experimented with. Next best was another Change Level C, Next best was a -E Change Level B (5CB dated). So what I can confidently tell you is the later the revision generally speaking the better the carb. will run!
For 1.08 C5ZF carbs missing original tags, if you look at the base mold dates (on very bottom) I've found the "9-1-64" mold dates generally always run better than the "7-17-64" and "7-27-64" mold dates. I've seen the 7-64 dated bases with tags up to 1965 Change Level B; I've never seen an original tagged 1965 Change Level C with the 7-64 base mold, just 9-64. Therefore I like the 9-64 bases better from a run standpoint.
I have never researched this in depth (and have no plans to), however I suspect the big or small numbers (one or other) on the bottom of the booster venturi may also indicate booster revision since the boosters out of a 1969 HiPo service replacement C6ZF-C seemed to be higher than the '64/'65/'66 factory assembly line HiPo carb boosters I looked at the bottom of. Just a suspicion.
Both of the rebuilt Autolite 4100 carburetors I have tried are the C5ZF-D model (car has an automatic transmission). Tags are missing on both carburetors so I don't know the date codes or change levels. I don't see a date stamped on the foot of the first carburetor (picture below), that seems odd. It does have the hot idle compensator in the air horn. Wasn't the hot idle compensator phased out on later revisions? The second carburetor, which is installed on the car now, has 9-1-64 stamped on the foot so based on what you said, I'll focus on tuning this Carburetor.
Everyones help is much appreciated! Thank you.
