[Pete Munroe]

You can ALWAYS spend more money later...like some of the fellas posted, what are your plans for the car? Street mainly?...keep the small carb for the torque.

I just had the opportunity to swap out my 750 dbl pmpr for a 650 dbl pmpr for the weekend.

(Hyde....care to swap out the Webers for a weekend?)

After an open track weekend at ButtonWillow raceway with the Pantera Club I would report:

the engine starts about the same, better?
seems to idle with less fumes
otherwise runs about the same/better? as with the 750.

The engine is 289/347, cam a mild roller, 224/228, TF heads, max rpm with the chip is 6000.

The 650 has 67's in the primaries/73 secondarys, the 750 has 73's/80's

There are not many points on a tight road track where you are at max RPM for more than a few seconds, and once I am at 6000, thats it...so more carb isn't going to help me rev higher. (could change the chip to 6500 but wear goes up with RPM so I would rather get lots of events on the engine rather than see the 500 RPM on my top speed)

For the street and a tight track, torque is better...for the drags HP is better.

You have the 600 carb in hand, RUN it...when you really need more to go drag racing or serious track, or get spanked BAD on the street...get the bigger carb and a dyno tune.

Above all, HAVE FUN, if you want braggin' rights...go ahead and get the big carb and dyno tune...see what the engine can do and frame the dyno sheet!

I would like to have dyno sheets for a range of carbs just out of curiousity...this stuff is Sooo much fun...

Pete