being an almost absolute newbie may I ask what may appear to you guys a simple question /answer isuue?
I wish to fit a carb from a manual vehicle to an auto trans vehicle .Where are the pitfalls ?? what is the big deal here ?? The vehicle to be fitted has a 425 toro with th400 trans ,the donor vehicle a 70 chebby manual trans
CHEERS MIKE

 

All Q-jets use the same manifold bolt pattern. The three major differences between the Chevy style and Olds style Qjets are the inlet, the throttle arm, and the choke. All Olds Qjets use a straight-in inlet. The Chevy carbs have the inlet facing the passenger side of the carb. You'll need to fabricate a new inlet pipe to match. The throttle arm may or may not hit the Olds manifold. If it does, you can use a spacer to jack the carb up to clear. If the engine is still installed in an early Toro, a spacer may give you a hood clearance problem. Depending on your Olds, the Chevy throttle arm may or may not have the correct connection points for the throttle linkage. The stock manifold for a 425 used a divorced choke (thermostat coil in the manifold with a linkage to the carb). I don't know what this carb comes with, but it probably doesn't match up.

Finally, the carb jetting is almost certainly not correct for your engine and car combo. You'll need to dial that in yourself by changing the metering rods and possibly the primary jets as required.

This does beg the question, why not just rebuild the original carb from the 425?

 

THANKS JOE --that is great-I understand. The 425 will use a o4b intake and clearance to hood is unknown yet as the engine is going into a cadillac--not concerned really if adaptations have to occur here .
Joe, the 425 came to me without carb .

 

Don't forget that you won't be able to run an HEI distributor with the O4B intake. It is an excellent intake otherwise. If this is an issue you can always convert your points distibutor to a variable reluctance distributor with a Pertronix conversion kit.

In addition, if you need to rejet your carburetor I suggest looking in your loacal yellow pages. I found a shop that repaired small engines and rebuilt carburetors. I went into his shop and he let me dig through his collection of metering rods and jets until I found what I needed. This saved me some money since I didn't have to order them from Summit or the auto parts store.

 

YOU GUYS ARE VERY HELPFUL--TX HEAPS .I will go with the pertronix conversion .OLDS64, You gotta see the lack of available parts here to appreciate it . And very few mechanics here rate themselves as particularly proficient in rochester. An awful lot of holleys.So, as I have a brother in LA ,he will be hunting down the spares --jets etc
Am seriously considering flying to LA ,buying a pickup, loading it with parts from Ca,AZ etc and shipping it home
AGAIN THANKS
MIKE

 

thanks --went with you guys advice n bought a rebuilt 4 bbl qjet from a 66 olds auto trans --should be a good start anyway.
mike