67 L-88 1st Design Carburetor

[Michael H.]

Does anyone happen to have an original 1st design 3418A Holley for a 67 L-88? (Not the 2nd design 3418-1A) Need the metering body numbers that are stamped on top of the body. Thanks.....

Michael

[Clem Z.]

Re: 67 L-88 1st Design Carburetor

4963A this is from the holley parts manual. the 1A carb is 5247A

[Michael H.]

Re: 67 L-88 1st Design Carburetor

Thanks Clem. Just going through some boxes of parts that I've had for 30 or 40 years and found this still new in the box. I thought it might be 1st design 88 but someone borrowed my Holley book with all the old info so I couldn't look it up. This is a 4965, must be secondary side?

Wonder how many of the 20 L-88's in 67 had the 1st design carburetor?

[Clem Z.]

Re: 67 L-88 1st Design Carburetor

yep secondary side. does it have 2 small hole drilled into the wells from the jet side above the jets.

[Michael H.]

Re: 67 L-88 1st Design Carburetor

Nope, no holes at all in the back side. Also, the only number stamped on the body is 4965 with no carb list number.

This body is in a Holley box but if I remember correctly, some of the Holley parts that GM shipped were double boxed, the Holley box inside of a GM box.

I remember a LOT of changes that this carburetor went through in late 67. Both metering bodies and all four corners of the jetting were changed. Was quite confusing because of the stagger jet configuration and if I remember correctly, Holley listed the jetting side for side backwards from the way the GM parts book listed them. I think this may have contributed to at least a few engine failures because there was quite a difference in LH/RH jetting, especially for the primary side.

[Clem Z.]

Re: 67 L-88 1st Design Carburetor

i remember having a secondary metering block one time with these exta small holes and GM told me it was to feed more fuel,richen up, the secondary side instead of larger jets. i do not remember what carb it came from. i will check my metering block supply and see if i still have it. we did this on both the pri and sec. side metering blocks when converting to methanol to get enought fuel thru the carb