Walbro carb help, HDA 98 vs. 35B

[LuckyRookie]

I'm hoping that someone can educate me on the potential difference between a Walbro HDA 98 (from a Husqvarna 246) and a HDA 35b (from a Husqvarna 254xp). I am rebuilding a 42 special for a good friend of mine and am curious if there is any actual difference between these two carbs that I have at my disposal. They seem to have the same (or darn close) bore and venturi diameter. Obviously they have different shafts, but those can be swapped if necessary. I'm just curious if the 35b has a larger main jet or if there is some performance reason to choose one over the other. Thanks and also let me know if anyone has advice on either 42 special or 246 porting.

 

[LuckyRookie]

I was afraid this wouldn't be a subject that a lot of folks had insight about...

 

[giver]

Check the choke side of the venturi there will be a number cast inside the carb, that is how many 64ths the venturi is and you can pick the bigger one.
If there is 35 cast in the venturi it is 35/64ths

 

[LuckyRookie]

Thanks, I appreciate the insight and response. I have measured the venturi diameter of each carb body with calipers and they are identical for all intents and purposes... So, that is not a deciding factor between the two. I was just curious if there was some difference in the main jet size or some other feature which would suggest one would be better for performance than the other.