what's all these extra holes for 391 c4tf i think

 

Welcome to FTE!

Possibly the tach drive and connections to the governor.

I think there are some illustrations in the tech thread . I'll look for them later.

 

Picture of vacuum lines from carb to distributor back to governor as best I can tell:

https://cimg6.ibsrv.net/gimg/www.for...b8bcb356c.jpeg

More links including complete shop manual adjustment and illustrations here:

https://www.ford-trucks.com/forums/8...l#post19447467

 

You are not alone in having distributor woes. Excellent pictures and illustrations here, as well as some shopping tips:

https://www.ford-trucks.com/forums/1...l#post21344069

 

Recently I bought a 390 with some sort of 5 speed attached for pennies to put in my dads truck with a worn 6 cyl and 4 speed upon closer examination it was a 391 so I'm working on getting parts for it

 

So thats what they are is there a part number for the tachometer

 

You should check the mounting, front accessory drives, and fitment of the transmission under the cab.

The 391 is certainly powerful enough but it won't act like a pickup 390. It is governed to under 4000 rpm which is probably ok.

 

I wasnt going to hook the governor up and as far as the transmission goes its bigger but not that much bigger also going into an m715

 

If you change the ignition to Pertronix you can set the Rev limit to 4000. Rev limiters are your friends with the FT engines.

 

Which Pertronix kit/set has rev-limiting capability?
I've installed several 1281 kits, and AFAIK it doesn't have that capability, but I'd love to know that it does.

[later]
Found it: 71281 has rev-limiting . . . at twice the price. I don't believe that product was available in 1999, when I first began installing the 1281 kits.

71281 installation instructions, including how to set the rev-limiter.

The rev-limit range is 4000-9000. 4000 is a bit high for my FT. The '73 Shop Manual sorta implies (in the Constant Altitude Adjustment section, starting on 23-20-05) that the governor should be set for 3500 (or 3900) at sea level. 3600 under load, 3900 no-load. The adjustment sections for the Vacuum and Mechanical governors don't say anything about an RPM setting, humorously.

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A problem with ignition-based rev limiters is fuel dumping into the exhaust when ignition is cut off but fuel is not. This is different from OEM rev limiters on modern FI systems that cut fuel to limit RPMs. It'll prevent over-revving, but at the risk of blowing a muffler (BTDT: 1980).

The OEM governor is much more graceful on a carbureted system. But dirt is the enemy of vacuum systems, and the oil-bath air cleaner frequently isn't serviced, and the cleaner's base gasket (or square-section o-ring) get lost or damaged, which lets crud into the distributor mechanism.

 

A light foot is a better governor than all that I wasnt planning on using the governor at all just wanted a 390

 

A 390 can tolerate revving. A 391 can't. People who've maintained the FTs in actual service fleets have found that running them much over 4k breaks things, like ovaling the rod ends. They are designed to be slow and last a long time.

An observant and educated driver doesn't need a "nanny" (governor), except for the occasional mishap. A sloppy driver can easily take out an FT in a day, just by driving by ear and thinking that it can be rev'd like the engine in their Galaxy/Fairlane/T-bird. Lots of FTs are being run without working governors, but I bet the ones that remain in service longest are either single-driver rigs or have functioning governors.

 

Well i was going to put 390 pistons heads and intake on it but im more interested in a mildly powerful motor that'll last longer hence why i kept the 391 as opposed to tracking down a 390 and doing something more standard and probably cheaper

 

I don't know much about FT vs FE, but just swapping the rods & pistons should make much of the difference in the rev capability, from what I've read. My limited understanding is that those were the major parts differences: the FT stuff is heavier and lower compression (for good reasons). If you turn an FT into an FE by changing the parts you mentioned, then the rules be different.

(leaving aside the cast crank (330MD) vs forged crank (330HD, 361, 391))

 

Anyone got a source for an oil pump on that 391