I've seen several things online about 4bbl vs 2bbl carbs on this engine. What about the Holley 350 cfm 2 bbl? Just looking for a little more power. It seems to me it takes forever to get to 45 mph in my truck with the throttle down. It's a 3 speed with pertronix ignition. Maybe I don't have it tuned right. Any info is much appreciated. Thanks.

 

Get it tuned up, the 352 has plenty of power and will run your truck just fine.


John

 

Thanks for your reply. I've changed spark plug, wires, coil, cap, vacuum advance, so far.

 

There's probably more commonly held misinformation about carburetors out there than almost anything else. A bigger carb will often make your truck run worse and wash out the rings, dilute oil, etc. And send more $$ out the tailpipe.

Remember too, these trucks weren't designed with snappy acceleration in mind but being able to haul heavy loads up steep grades, etc. They are geared, and tuned for this. You can tune them for better acceleration and performance, but a bigger carburetor is probably not necessary. Ford tended to install carburetors a little bit on the small side, it is true. This makes for a bit better acceleration with heavy loads off the line. Large CFM carburetors come into their own at high speeds and high RPM. They tend to not idle well and have hesitation problems and other issues. A properly "sized" carburetor has good fuel atomization properties, due to the venturi diameter. Crisp throttle response - and good acceleration.

If you use one of the CFM calculators and play around with the numbers it starts to make sense. If you are drag racing - full wide open throttle, that's one thing. Then plug in say, 75% efficiency and your typical highway cruise RPM for your rig and the recommended CFM will be almost exactly what Ford provided as OEM.

Sorry for the lecture, ha ha.

Get your engine timing and distributor advance curve setup right and see what you think first.

 

Thanks for the info. I'm definitely not gonna race this truck. Just seems something isn't right with the truck. I give it a lot of throttle and the engine/exhaust makes a lot of noise but the truck seems to be moving slowly lol.

 

Not trying to be a smart a&& , but is the clutch slipping?did you check the timing?
I'm trying to help, let's get back to basics

 

To be honest don't know if clutch is slipping and the timing is set at 10 if I set it any lower it misses really bad going down the road. Could my dizzy be bad?

 

Don't worry about the dizzy right now. Look into setting the initial timing using a mechanic's vacuum gauge, just for grins. Here's why.

Dampers are often known to slip off their index because the rubber bonding deteriorates. They need to be replaced when this happens, not just because the timing marks are no longer usable. But... For now, this is may be part of the problem.

Your ten degrees BTDC indicated, might actually be closer to Zero in reality. Using a vacuum gauge to set the timing avoids all this and sets it at the optimal point without the use of the damper marks or timing light.

 

When you let the clutch out, does the engine rev up and the truck just start to move slow? Or if you let the clutch out does the truck jump forward? A slipping clutch will make the truck just creep along

 

Have you checked to see if the centrifical/mechanical advance in the dizzy is free. Not many people think to put a couple drops of oil into the felt under the rotor as a maintenance thing. Grab the rotor with your fingers and twist in direction of normal rotation. The rotor and shaft should rotate and when you let go it should spring back to original position. WITHOUT this advance working properly, your going to have a lazy engine that wont rev properly or produce the power it should. This 352 in its stock state of tune should fly in your truck. Do all the test others have mentioned but do this first, it only takes a minute and cost nothing.

Engine could have a very worn timing chain, just another thought. I don't know if it would run if if jumped a tooth. You can check its degree slop, but do the other things first.

 

One of the better improvements I made to my old 352 is a factory 4v intake and factory 4v Ford Holley carb (c.1983). Actually maybe going to Duraspark was the best upgrade, but this really helped a lot. The rest of the engine was bone stock.

 

Aware contrary to popular belief; having swapped both 65's from 2bbl to Holley 4bbl, to include headers, not that I regret the swap, just that I did not find any significant difference; particularly with the 302? I found the 65 with the 302, T18, and 3.54-1 ratio rarely; if ever, did I get into the secondary, with a max rpm running below 3k. Now faced with dilemma, the headers on the 302 need to be replaced, either reinstall the 2bbl intake, stock exhaust, and purchase a 2bbl Holley; or purchase another set of headers???

 

Thank you all for the info. My wife got sick so I haven't been able to post lately. My heads ar bone stock never been touched what should I do with them? What 4 v intake and carb will fit my truck? 390? 352 4v? Thanks

 

I turned rotor and it was very stiff and barely moved and did not return on its on.

 

Did you try rotating in both direction and if yes the advance is probably frozen. Rotate the engine until your timing mark is at TDC, remove dist cap and see if rotor is pointing to #1 plug wire in the cap. If not turn engine over once more to TDC again rotor should point to#1. Remove the distributor and set up in a vice, remove vacuum unit, then the plate the points and condenser sit on. Underneath you will find the advance mechanism. Take out the little felt in the center of the shaft under where the rotor sits. Lube it all with a rust penetrant. You want to try and free up by holding the dizzy drive gear and grabbing the shaft where rotor sits and gently working back and forth. I use pliers on the drive gear and a vise grip at the rotor end. GO EASY, you don;t want to break anything.