#180 Six Pack Throttle Plates?

[PurpleBeeper]

Looking at my outboard carbs, I see that the two sets of throttle plates don't match. The rear carb has thicker aluminum #220 throttle plates in it (one's from '69 that are supposed to stick sometimes) and the front carb has #180 thin, steel throttle plates with some type of washer/shim on the screws (inside slot in throttle shaft where the throttle plates slip into the shaft). This looks odd, but also looks like it will allow slightly more airflow through the carburetor + it has absolutely no indication it will "stick" in the baseplate throttle bores... the better design of the two in my opinion. The rest of the baseplate(s) look identical.

Is my front baseplate possibly from a Chevy 427 or Ford 390 six pack setup? Does it really matter? What do guys think?

I'm planning to go through my box of six pack carbs & see what other baseplates I have. I'm mainly concerned that the plates are the same + they don't stick. It looks like I can smooth out the edges of the #220 aluminum ('69 Mopar) throttle plates so they won't stick (not really that bad, but I want 110% smooth operation) with some 1000-grit sandpaper on some of the edges.

Any other thoughts/suggestions on this?

 

[440+6]

some of the 69 outboards would stick a bit after a heat cycle.
I think only mopar outboards had the idle mixture screws in the outboards.

 

[62MAX]

There were issues with the #199 plates sticking,sometime they could be cleaned up and worked,sometimes not,you had to be careful with what you did,if you sand the plates you can change the angle they are cut at and could make it worse.They were replaced with # 226 plates,that is the "only" correct plate for the end carbs,aluminum plates in the end,steel in middle.GM carbs didn't have mixture screws in the end carbs,used 199 plates without air bleed hole,the main body were modified center body's which had different idle circuits and the center carb adjustment was all that was needed.

 

[PurpleBeeper]

Looking at the numbers more closely, my aluminum plates are #226, not #220. I swapped out the outboard plate with the thin, steel #180 throttle blades (also has idle adjustment screws) for another #226 aluminum blade plate so the two carbs would match front/back. I still am not sure what plate I have with the #180 throttle blades/spacers. Maybe someone in the past made their own throttle blades if replacements weren't readily available.... I bought these carbs in the early '80's.

 

[ragstorich]

Looking at the numbers more closely, my aluminum plates are #226, not #220. I swapped out the outboard plate with the thin, steel #180 throttle blades (also has idle adjustment screws) for another #226 aluminum blade plate so the two carbs would match front/back. I still am not sure what plate I have with the #180 throttle blades/spacers. Maybe someone in the past made their own throttle blades if replacements weren't readily available.... I bought these carbs in the early '80's.

 

[ragstorich]

on the "butter flys" / throttle plates both the 340 and 440 out board plates are #199 now for the last several years now and as you probably know the idle holes are different sizes , i stock both throttle plates..hope this helps.

 

[PurpleBeeper]

Thanks rags, but I ended up just making sure my front/back were the same & went with another #226 aluminum throttle blade base plate I had that matched. I did not know the holes were different, so thanks. I've got all outboard blades drilled to 3/32" and it seems to be working in my combo