What size carbs?

[Ian Anderson]

I have seen a set of 44 IDF carbs for a good price.

Are they big enough for a 302?

And are they the better carb when compared to IDA carbs

Thanks
Ian

 

[Malcolm]

If I remember rightly most guys use 48s on a 302 for best results. And I think the IDA are the ones to have. But stand to be corrected on both counts, after all I am only a Holley man!

 

[Randy V]

Nothing wrong with the 44 IDF carbs.. They are of smaller venturi (choke) and won't produce the maximum HP, but will more than likely be more tolerant of street use due to their smaller size yielding a better and more consistant vacuum signal.

 

[Cliff Beer]

Ditto what Randy said. The smaller chokes v. 48's will give you a bigger vacuum drop and flow rate (and hence better atomization) than the 48s for a bit more street friendliness, will work fine. You can probably get a tad more hp/tq out of the 48 IDAs but it's not much.

There's a few threads on here as to suggested jetting for the 44IDFs and a 302.

Have fun synching those carbs. I suggest you make sure your linkage is absolutely first-rate as synching them up is made more difficult by sloppy linkage. Worth having some extra jets laying around as well.

Make sure the progression holes drilled in the throats by the butterfly are all the same. If they're not then don't buy 'em, you'll never get consistent mixture across all four.

 

[Glenn B.]

Unless you are racing, the 44 idfs will be smoother on the bottom to top transition and have better low end response. I have them on a 6.3 liter small block Chevrolet and they are just fine. I'm giving up 2-3% of the available horsepower on the top end by not switching to 48s, but the overall driveability is worth it.

Weber tuning is all about interrelated components:
Venturi sizing/jet sizing/emulsion tube sizing combined with fine adjustments of air screws. Unless you are prepared to study extensively and go through a protracted trial and error phase, using an experienced tuner is worth the expense.

44s are more than adequate for a 5 liter. Both setups will work. It all comes down to what you want and what you intend to do with the car.

 

[Jimmy P]

I agree with my learned friends above. I have the 44 IDF's on my engine and have found them to be excellent for street use which is what my 40 gets used for most often.

 

[Glenn B.]

One last comment....If you are passionate about being as close in detail to a "period correct" appearance on the engine, then the 48s are the choice.

As you have found a good deal on the 44s, only you can make the decision if that factor carries enough weight to justify the price difference.

 

[Ian Anderson]

I think I'll pick them up so thanks for the advice everyone

They are advertised at £350 on a Rover Manifold - sure they are used and will need rebuilt, and a manifold purchased but a new set on a Ford Manifold is about £2600


Ian