Help with metering block gasket

[6s855]

I have a 1985 Holley reissue 715 3259-1 that's dribbling gas inside and outside its' bowls. The front metering block is marked 4756 and rear is marked 4560 the same as the original 65/66's.  Are they the same?  I don't know, but clearly it's time to check for float problems and replace the gaskets.  Since this is a 4150 style carb I could try to match up my current gasket holes with pictures I see on various vendor ads, but there's no guarantee what's in there now is correct.  Here's a typical ad for 4150 replacement gaskets:

https://www.summitracing.com/parts/hly-108-200

I'm hoping someone with a reissue carb has been down this road before and can give me a hand.

[mygt350]

Original List 3259 715 from a 65 has different metering blocks than the List 3259-1 and issues. But, gaskets are identical. I have a reissue and found one of the two asked positioning posts was a bit long and was not allowing block to sit perfectly flat which allows gas everywhere...Remove gaslket, put plate against main body and see if it is flat or rocks. If it rocks, zero in on the pins. I had to file bit off mine to get block to sit flush. Originally thought I had warpage issue...Get known straight edge and put it on Bloch surface ce and see if light shows thru. Same for main body. I found one squirter that when squegded in, created a lit that may have caused a high spot. Small file and patience fixed both issues.  I get my gaskets from Jarold at AllState carbs. allcarbs.com. They know List 3259 carbs

[mickmate]

I believe the 3255 and 3259 are the same on float bowl gaskets. I have had to use a Mopar gasket on my 3255 with the little bump out on one edge and different block-offs. They are different gaskets to a 4150.

[6s1802]

Just went through this with mine. I used the blue Holley gaskets and the leak stopped. I did notice there was moisture residue in the secondary bowl and on the e metering block and the bolts had rust on them from the ethanol in the gas.

[6s855]

Thanks 6s1802.  I'll use the blue holleys marked 108-200. Appreciate the responses.

[trotrof1]

Just to add, if you replace the fuel bowl screw sealing washers best to use the original style rather than the hard nylon type.

[JohnSlack]

Good information thank you all.


John

[Drew Pojedinec]

I had a lot of gasket issues with metering blocks. I threw away probably 500 gaskets that were brand new due to fuel pulling through them.
After going through a dozen different types, I bought a load of them that seal perfectly.

As mentioned above, block and main body need to be flat and have nothing holding it off.

If you want these parts, drop me a line and I'll get the mrs to pull them.

I'm also available for more detailed assistance via email if needed.

[6s855]

Thanks Drew.  Will get back to you after the Christmas chaos is over.