1st post on my 429 Mustang - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

Bigen · 09-04-2006, 10:24

About a month ago, I bought a 71 mustang fastback.

I was told the engine wasn't original and was a 351, but upon further research, appears to have a Weiand 8012 Stealth intake, which is for a 429.

I was able to get the casting number off of one of the heads, C9VE-A.

So it is a 429!

I’ve changed the distributor cap, rotor, spark plugs, plug wires, thermostat, flushed the radiator, and changed all of the fluids.

Doesn’t sound like much but when you consider we have a 3 month old baby boy in the house, it was hard to get that little bit of work done!

However last weekend I took my 15 year old son out for a drive. The car still starts beautifully, and idles nice.

While we were out driving it, when I really hit the gas petal hard, the car hesitated, spitted and sputtered. I would let off the gas and it went back to running fine. I tried slowly depressing the gas petal and it would rev up and do fine. But every time I hit the gas petal hard it would spit and sputter. I tried spraying out the carburetor with carburetor cleaner, but it didn’t seem to help.

I took my car to a friend of mine who builds hot rods. He suggested that we change out the power valve in the 4160 750cfm Holley Carburetor, which we did.

We then changed out points for pertronix igniter, and a flame thrower coil, got out the timing light and adjusted the timing. We adjusted the timing from 0 advance to 10deg advance, did have something strange happen there. The plug wire to the #1 cylinder would only fire when pulled out of the distributor. I could hold it just above the distributor and it would fire like crazy, but when plugged in it wouldn’t fire the timing light? Regardless the car is still backfiring through the carburetor. But I think I have a bigger problem now.

While we were adjusting the timing, I started hearing a loud squeaking or chirping that seems to come from approximately the #4 cylinder.

I’m guessing something is going wrong in that head??

When it rains it pours!!!

Brian Stone · 09-08-2006, 06:48

I would go ahead and put a rebuild kit in the carburetor--that is most likely the source of the hesitation--the acceletrator pump is probably not working properly in it. The squeaking from the #4 cylinder is probably a rocker arm not getting enough oil--I would take off the valve cover and remove the rocker arms around the area of the noise--will be obvious if on of them is dry. If so, the hole through the pushrod is probably clogged up.

ricehater · 09-26-2006, 11:01

can someone give me a brief history of the 429?

Paul Kane · 09-29-2006, 23:32

1968-1973 production.

All parts between the carbureted 429's and 460's are interchangable except the pistons and crankshafts (unless swapped as a set), as these are the only parts that differentiate the two engines.

Paul