Thanks in advance for any advice. I'm being told by my shop that the Holley 350 just put in isn't a good carb for the stock 351M engine in our '73 F250. The truck will be lightly used, but used. Farmer's Market type of stuff.

 

It would seem alittle small. Hows it drive?

 

That is plenty for a 351m.

What is wrong with the stock carb?

 

Well, what I didn't tell you was that they've had the truck for almost a year. I found out why yesterday afternoon when I went by that nothing is really wrong with the fitment. He let it sit too long and the seals and such are messed up. Someone else told me the linkage was incorrect. I'm picking it up in a minute. Haven't driven it in over a year. About to pick it up. We will see.

 

I have been experimenting with a 7448 on my 1978 f150 with the stock 351m. It's actually the same size as the original Motorcraft 2150 1.21 that came with the truck, which is rated at 351 cfm. A lot of people will tell you it's undersized, go with the 500. I want economy and drivability plus plenty of power for things a ranch truck does, and I can tell you so far I am very impressed with this little carb. It runs like EFI, has never skipped a beat here around the place. Awesome throttle response, crawls around great, yet will pull away at wide open throttle - throwing gravel in 2nd, fish-tailing in 3rd and just pulling away in 4th while climbing a grade. Punch it hard anytime anywhere and it just goes, smooth as glass. I am taking it out on the highway in a couple days and will put it through the paces there, see how it feels at steady highway speeds.

 

So an update if anyone is still out there...

I picked up the truck two days ago and the blowback is crazy. I know there will always be some. The PCV port on the carb is unused if that matters. It drives fine when I give it gas. Soonafter though, it starts to putter out right before idle. I have to tap the gas to get some into the carb. The fuel line has a bad bend in it, and it runs right next to the radiator which seems to be crazy hot for just 15 minutes of leisurely city driving. I know the 351M's run hot from what I've read, but the engine that was just "rebuilt" shakes a bit. I've bought an Equus gauge to check the actual temp. I'll probably run a T at the water temp send to keep the factory gauge. It runs at about 70-75% towards Hot after a quarter hour of driving around town. On a cool day. With an empty bed.

I found out the reason they told me to replace the carb was because it sat so long. They think it went bad and told me to ask about the warranty. Of course, I took it to them brand new 11 months ago. And it sat at their garage. And the carb went bad, so they say. My head is definitely hanging down thinking about all of this. I am replacing the fuel pump today. The part should be in around 2 p.m. 20 bucks and I'll learn how to put in a fuel pump. I've never done it before, but I have neighborly backup just in case. Though they are Chevy guys.

So, the Avenger is just fine. It gets up and goes as much as the Hyundai's next me. Could the issue be the kink in the line? This is all first time stuff for me, but I'm going for it. The problem is this truck was supposed to be good to go. You know, $1500 engine rebuild. They also replaced the radiator. I need to figure out how to make this right, but I definitely won't ever take the truck back there again. They could have ruined my carb and who knows what they did to the engine. It wasn't until I started asking questions from I've read on these forums and other posts that they told me why they thought I needed a new carb. It's a freaking mess most of you would never deal with as you do all this yourself. Good for you.

 

Blow by on a new rebuild?

No PCV?

Yes, stay away from whoever did that.

Once you get it running better, sort out the PCV. The OEM PCV intake was a plate under the carb. Make sure the PCV port on the carb is plugged.