When changing carb types, you’re probably going to run into a few road blocks. We picked up our carb at a swap meet and called Edelbrock to get their instruction booklet to help with tuning (most companies will send you instructions), plus they threw in a new base gasket. If you’re putting an Edelbrock on a factory cast-iron Q-jet intake, you will need the company’s PN 2696 adapter. Our engine already had a Performer intake so we were all set. When changing carb types, you’re probably going to run into a few road blocks. We pic It’s obvious you can’t reuse the entire hard-tube fuel line from the Q-jet, but you might be able to use part of it. If you plan to use the stock line again, use a flare wrench on the fuel line fitting and hold the filter fitting with a 1-inch wrench. If you’re not concerned with the line, you might even skip this and cut it off in the middle with a tubing cutter, then you can route the new fuel hose from the hardline to the carb inlet. It’s obvious you can’t reuse the entire hard-tube fuel line from the Q-jet, but Make sure all of the linkage and vacuum lines are removed from the carb. Luckily, our car doesn’t have any accessories or emission components so there were no vacuum lines to wreak havoc during the installation. If your distributor has vacuum advance, note where it attaches (to ported or manifold vacuum) on the old carb. With everything out of the way, unbolt the rear nuts and two front bolts that hold the Q-jet to the intake and lift the carb off. There will be fuel in the bowl still so dump it in a gas can. Make sure all of the linkage and vacuum lines are removed from the carb. Luckily, our car We opted to bolt down the new Edelbrock with studs instead of bolts. Either will work. Set the carb over the intake and note which holes are the correct ones, as the Edelbrock intake is drilled for two carb-base patterns. Tighten the studs by locking two nuts up against each other. It’s a good idea to plug the intake’s plenum hole with a rag so you don’t drop stuff into the engine. We opted to bolt down the new Edelbrock with studs instead of bolts. Either will work. Set Fortunately, we were ready to face what could have been a problem with the transmission’s throttle valve (TV) linkage. We knew that our late-s overdrive trans would require a different kick-down bracket when going to the Edelbrock carb. This bracket is held by the left rear carb stud and guides the throttle linkage and the TV cable. Having the wrong bracket, adjustment, or not hooking this up could mess up your transmission’s performance. We found this bracket at a performance trans shop and GM offers them new under PN 22504927. Fortunately, we were ready to face what could have been a problem with the transmission With the studs and new base gasket in place, drop the carb onto the intake. Dont forget to put the new linkage bracket in place. Tighten the new nuts evenly as you move around the base. You dont need to reef on these nuts--the base of a carburetor can be cracked with a surprisingly low amount of torque. With the studs and new base gasket in place, drop the carb onto the intake. Dont for The new GM bracket worked great to point the linkage in the right direction, but connecting it to the carb posed a little work. The Edelbrock carb didn’t have a linkage stud, but we were able to scavenge the one from the Q-jet and luckily it bolted in place. Be sure to work the linkage back and forth several times to check for binding. It’s also a good idea to have someone get in the car and slowly push the pedal to the floor to make sure the primary and secondary throttle blades open and that wide-open throttle is achieved. The new GM bracket worked great to point the linkage in the right direction, but connectin We didn’t get so lucky with the kick-down linkage stud. Again, we used the one from the original carb, but had to slightly enlarge the hole in the carb’s linkage to bolt it in place. We’ve since learned that Edelbrock has a variety of tranny kickdown studs (PN 8018) that bolt right on to its carbs. A cordless drill and a variety of bits got us to the right fit. The slight mod worked well and we connected the TV cable followed by a quick self-adjustment of the cable (necessary with a TH700-R4). We didn’t get so lucky with the kick-down linkage stud. Again, we used the one from t Over the years, our original fuel line had been twisted around and wasn’t in the best of shape, so we opted to run rubber fuel hose all the way from the pump to the fuel inlet. This also allowed us to easily install a filter inline. We had to get a brass fitting with a nipple outlet that screwed into the fuel pump outlet in order to connect the hose. Over the years, our original fuel line had been twisted around and wasn’t in the best Carefully route the fuel hose up the front side of the block to the fuel inlet. Make sure it is away from the exhaust or any sharp edges that could rub through. Also, keep an eye on the fan and other pulleys. The Edelbrock carb doesn’t have an internal fuel filter, so you have to put one in the fuel line. A few plastic zip-ties or a hose clamp will keep the line secure. If you plan on running at the dragstrip, remember that the NHRA allows no more than 12 inches of rubber fuel line on the entire car. You may need to buy and bend some hardline. Carefully route the fuel hose up the front side of the block to the fuel inlet. Make sure Here was our last hurdle. With the engine running and no leaks, we thought we were done and went to put the old air cleaner on. It didn’t fit. The extra-low base of our air cleaner wouldn’t clear the distributor. The solution was a trip to the speed shop to find a plastic spacer. A 3/4-inch spacer (PN 8092) from Edelbrock did the trick. One thing that did fit was the original throttle-return spring. Here was our last hurdle. With the engine running and no leaks, we thought we were done an The addition of the spacer put the top of our air cleaner just high enough so that the original retaining stud didn’t peek through. We couldn’t find a screw to work and were forced to buy a piece of threaded rod and cut it down to fit our needs. Don’t forget a wing nut. CC The addition of the spacer put the top of our air cleaner just high enough so that the ori How many times have you heard this? "Yeah, I'll make it to the track Saturday. All I gotta do is drop on my new carb before the races." For some reason, this guy usually doesn't make it at all, or he shows up in his girlfriend's Jetta about an hour before the track closes. Unless you're swapping a Holley for a similar Holley, or a Quadrajet for another one, the job isn't going to be as easy as it seems. There are plenty of obstacles to run into, including problems with gaskets, mounting hardware, linkage, brackets, fuel lines, vacuum lines, air cleaners, and more. To prove our point, we pulled a worn Q-jet off a small-block and replaced it with an Edelbrock carb we picked up at a swap meet. SOURCES Edelbrock Dept. 5.0 2700 California St. Torrance CA 90503 310-781-2222 www.edelbrock.com Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!