IDF vs. IDA ?

Scott Calabro · 05-01-07, 10:23 AM

Hello Gents,

I am in need of advise of the differences between these two models of carburetor. They will sit on top of a + .030, 11 to 1 C/R 289.

I shooting for only 375-400 HP.

Comp Cams S/R 246X246 @.050, .586 lift both sides, 110 deg LSA
AFR 180 heads
Ross flat pistons
5.4 in rods

Seeing as though Top End Perf. currently has quite a sweet deal on an IDF setup, I thought I would ask some folks who are "in the know" when it comes to these carbs.

Thanks in advance !
Scott

Larry · 05-01-07, 01:43 PM

IDF's are more "streetable." I have IDF's on a 289 with about the same setup as you are talking about.

Rob · 05-01-07, 02:10 PM

Scott,
For the same reason as Larry, I too will be running the IDFs on my vintage 289 set up.

Andy 8V · 05-01-07, 11:15 PM

It's your car and you are the only one to please. The essence of a GT-40 is not a budget sedan with a bargain induction system. I love GT-40s with hipo 289s and 48 IDAs. In the event you sell or trade your car in the future I believe the IDAs would make your car more desirable. But in the end, you the only one that matters in this choice.

Bill D · 05-01-07, 11:32 PM

A hi compression engine like yours will do better with IDA's

David Briggs · 05-01-07, 11:33 PM

I have a Tiger with IDA's and IDF's on my Gt40, both run great. If you are not building a race motor, I don't think that it matters. IDF's are newer, slightly improved and probably best way to go. The only major difference is that the idle mixture screws are a little easier to get to on the IDA's and the idle circuit air corrector can be changed.