Big Block Towing Motor

[kfactor239]

Ok I just got my 86 C30 dually home with a big block 454 and 4.10 gears. It's awesome. It is completely stock and untouched. Here is the bad though. All that emissions crap is all over the motor. I plan on putting headers and exhaust on it pulling off that intake and old q-jet carb for a good edlebrock and a holley 600. Thats all fine and dandy till I look at the belt system... Where would I find a good serpintine belt system and still keep my hydroboost brakes? I want the ac to work I want the cruise control to work I want my hydroboost brakes to work.

 

[da_raabi]

Why do you want a serpentine system? I'd stick with the flat belt for the alternator, and the two v-belts for the p/s and a/c pump. Its a simple system and its cheap.

Also, why do you want an eddy carb? Something wrong with the quadrajet? I have the exact same setup as you and it runs great. My OEM exhaust manifolds are like mini-headers and the previous owner plugged the air tubes with pipe plugs. I removed the air pump, disconnected the EGR etc.

I'd upgrade the cam to an R/V cam before you do any of that other bologna.

And as long as your power steering pump works, your hydroboost brakes will work.

 

[kfactor239]

I was thinking of a Holley carb on an eldebrock manifold just to clean things up. Same with the exhaust. The stock manifolds have that belows on them i dont like. I guess the factory brackets would work but i would have to do some homework for the right belts.

 

[kfactor239]

As for the carb that old qjet is pretty worn out. It's got so many vacuum hoses on it that it makes my head spin. I prefer the keep it simple approach.

 

[Georgeb]

As for the carb that old qjet is pretty worn out. It's got so many vacuum hoses on it that it makes my head spin. I prefer the keep it simple approach.

You could look for an older non smog QJet.

 

[kfactor239]

Is the qjet going to work better? This is my first big block so I'm open to suggestions.

 

[Georgeb]

Is the qjet going to work better? This is my first big block so I'm open to suggestions.

A well tuned Q-jet properly jetted for your engine with a good working automatic choke will work really well for you up here in the north country. An Eddy carb can too but you will have to tune that one too.

 

[kfactor239]

I live in Oklahoma our summers are over 100 degrees. I hate anything that puts hot air back int an engine. Like egr and other crap. Are Holleys not good on a big block? I have a racecar and we have to run a 500 2 barrel Holley so I'm comfortable with them.

 

[Georgeb]

I live in Oklahoma our summers are over 100 degrees. I hate anything that puts hot air back int an engine. Like egr and other crap. Are Holleys not good on a big block? I have a racecar and we have to run a 500 2 barrel Holley so I'm comfortable with them.

My bad on the location. For some reason I thought MN.....
Anyway, I still think the Q-jet would be a good carb.

 

[da_raabi]

I use a qjet down here in FL and we get the same heat. You can disconnect all of the emissions crap and keep the carb. It works fine. I have no air pump, egr, etc etc. The qjets will get you better gas mileage while maintaining power because of the different-sized throttle blades.

Look on RockAuto for the correct size belts, or just measure with a piece of string. Either way works.

 

[Quadrajet Power]

That Quadrajet you have is a fine design, especially for towing. Would be 800 cfm. If you remove smog stuff and want to get rid of hoses, just plug the ports and it will clean it up.

I can build that Quadrajet better than new for you and it will be much less than any new option. It will provide best fuel economy and power when you need it.

 

[80goldenburb]

600 cfm isnt enough for a 454. i put an 800 cfm QJ on mine and it really woke up. that would be best for towing.

 

[75gmck25]

I am using a Quadrajet from an '86 one ton on my '75, specifically because it is the most advanced Quadrajet design they made before starting to use carbs with electric connections. It has float bowls that hardly ever leak (unlike earlier Quadrajets), an adjustable APT for the part throttle transition, and other useful capabilities. Is yours all vacuum hose connections, or is there also a plug for something electric?

On that '86 Quadrajet there should be only three vacuum hose connections that are absolutely needed: one to the distributor vacuum advance, one large one for the brake booster, and large one running over to the evaporative canister to capture fuel vapor. All the rest of the small vacuum lines are for the hot air choke and the vacuum pull-offs on the choke. All these hoses make it look complicated, but none of them hurt anything for your performance. If you convert to an electric choke it gets even simpler.

If the Quadrajet is in good shape I would use it, since its CFM should be a good match to the engine. Rochester only made a few basic designs for the Quadrajet, and then GM set them up for whatever engine they were using with them. It is not unusual to find big block Quadrajets that are set up for 800+ CFM, and most of the small block Quadrajets can be easily modfied to flow that much.

Bruce