Well my question is for a stock 12a for street (not race ) use what is the better choice Ida or Idf 48 weber . And why . Thanks

 

IDAs don't have chokes, which can be a pain, but IDF manifolds look like they were made by 80s Volvo designers (all right angles), so...

 

you're in California, go IDA, choke isn't needed

 

Is that the only difference ? Tune ability is the same ?

 

IDA has longer runners and could be made longer, both hard to tune, my 48IDA starts good at 10 but takes about 3-4 minutes to hold idle.

 

Well i called weber , they said the ida is a larger carb body size with a different flange than the idf .The idf was made for off road racing and both don't have chokes . tune ability is the same with both carbs.

 

Between the two it is wither you want a side draft or down draft, the side draft manifold has longer runners, now from my experience with the side draft in a very light car, keep the sleeves in the intake for low rpm power and use the side draft, for out right upper end power; there are better carburetors than the weber.

 

IDA and IDF are both down draft

 

Side drafts are a big No No for me , if I want some low end I'll use a nickki carb . I dont know of any carbed car that has a runner that does a 180 . Racing Beat will tell you side drafts are not the best carb ether , and they have some experience that is hard to beat. In my experience down draft webers and modified stock carbs are the only way to go. I had a holly and it would cut out when I took a sharp corner ,use a lot of gas and would flood if I parked on a hill with the driver side higher than the passenger side ( or vise versa ).If there was a manifold for the idf I would probably use it , but since they don't I'm using an ida .Rio if you want to sell your down draft and manifold (12a) let me know.