262 intake/exhaust

61 UNI

New member
Let's beat this dead horse.
I have a 61 unibody with the 262 engine. The engine is ready for install. Originally my goal was stock look stock sound QUIET. I have converted to duraspark with msd box and modern charging. Idea here is for driveability. I only drove the truck one around the block before tearing down and the clutch was in pieces. I would like to know...
A) drivability of 223/262 with stock intake and exhaust
B) real world power gain from Clifford setup
C) fitment of Patriot header in 61 floor shift t98 from someone who has done it.
D) performance gain from dual offy with stock exhaust.
Thank you!


Well-known member
I can only comment on "A" as my 58 F-100 w/223 is still stock and in the immediate family since new. The 223 in stock form has excellent driveability when all systems are functioning correctly. There is lots of torque and the engine runs smooth and quiet (relatively, it has solid lifters). This is evidenced by the fact that first gear in the 3 speed transmissions was not synchromesh. You seldom need 1st unless you are starting from a dead stop. However, trucks are geared low (e.g. 3.73:1) so 70 mph on the highway is not something you want to do regularly.

The problems for driveability fall mostly in the distributor which you've already taken steps to correct. Points used to be a heavy wear item. In that era, tune-ups were performed every 10,000 miles. Often, points didn't last that long before they were burned and pitted. This usually resulted in hesitation problems that masqueraded as an accelerator pump malfunction that couldn't be corrected with carburetor repairs. Hence the age old saying, "90% of all carburetor problems are in the ignition system." Many have had problems with the load-a-matic distributors but I have not seen that. There are multiple points of failure in that system so I suspect it can be caused by a clogged passage in the carburetor, a defective spark control valve on the carburetor, or a vacuum leak anywhere downstream.

I seem to be heading in the same direction as you regarding my engine. That is, increasing power and torque to make the engine more tractable in today's traffic. I'm anxious to know how the distributor change works out. The factory carburetor is pretty small, anything larger should expand the RPM range a little with more power throughout. The second bottleneck is the intake manifold so the carburetor will need something to go with it. I'm not sure about headers but my history with other engines indicates they should be a worthwhile change if you're willing to put up with the additional noise and aware that they are tubing, like any exhaust pipe, and won't last forever. Not that there is a big choice but relatively small, long tubes should enhance your torque curve the best.

The final bottleneck is in the cylinder head. I wish I could test one on a flow bench to see if the siamesed ports are a problem or not. There was a project with our 10 port head on inliners.org but it seems to have died.

The last thing I'll mention is the 4 bolt main bottom end. It's more than adequate but it can become RPM sensitive if you go too high.

Hopefully, Bubba... will pop in. He's a wealth of information about the performance side of these engines.

Lou Manglass


Staff member
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Supporter 2019
I do have a question for you, what would be your goals for the 61 uni? By this we can guide in some the mods. In general though, those are great first mods by going to the better charging system and the excellent DuraSpark II distributor with MSD box. :beer: And congrats on getting a 262 these are getting to be hard to find engines that gives you even more torque to work with over a 223. There is nothing wrong with it being quiet I used to use nice long glass packs first then later went to the Turbo mufflers. I like them to be quiet for a bit more of a stealth sleeper and to a point you can still keep it kind of stock looking.

A. X2 yes the drivability is quite good with the stock intake and exhaust.
B. Can't answer this accurately though I suspect that it's quite good. I used the Clifford single 4V (Ram Flow) intake with a small Holley 390 CFM carb this is a great flowing intake manifold, don't think it's made any more though.
C. I haven't used the Patriot headers on anything though they look like well made headers and the company has. A good reputation. I have used the old style Clifford headers and they were nice quality and fit, don't think they make the old style headers anymore either. I don't know about their current parts since the passing of Jack Clifford but he was a genius with the inline six'es.
D. The 2x 1V Offy or Fenton is a great performance improvement over a stock intake. The single carb is too small and fuel distribution isn't very good. The duel intake goes a long way to fixing both of these issues, Performace is improve and even when using straight throdle linkage fuel economy can even be better. Combined that with a 2 to 2 1/4 inch free flowing exhaust system and you have a great system.

Good luck on your build. (y) :nod: