I had a 390 in a 1977 F-150, no it didn't come in it. I was given a 76 Camper Special engine for replacing a heater core in a 78 pickup. The owner had had several heart attacks and a couple of bypass surgeries and figured he couldn't do it. Once I discovered the secret, it took me 30 min to have it done.

I put the 390 and a C6 in the truck and actually found all the mounts, accessory brackets etc. in junkyards. I just cut the blanking panel out of one side of the radiator support so I could put in the proper radiator. With a 3.25 gear, it would pull pretty much anything you wanted, it also ran like a drag car, but could get 16-17mpg highway. I designed a dual exhaust setup and had my local muffler shop build it, both pipes crossed over to the right side with an "H" connection, dual Corvair Turbo mufflers mounted with the cross section oval vertical then dual 2 1/4" tailpipes ending up on a 45 degree angle where the stock single exhaust went. Hauled a Wolverine 11 1/2' slide in camper and flat towed an Omni with no problem.

 

Yeah, 390 swap in a 77-79 would be easy, especially if it had a 300 in it. 360/390 used the same towers as a 300, just in a different set of holes in the frame, plus the frame stands from 65-79 all swap easily.
The 65 I had not only had a well built 390 and NP435, but also had a 3.25 LS rear axle. 12-14 MPG was pretty normal for my driving style at the time, and gas wasn't even $1/gal, so I didn't bother with trying to stretch it any further, since it was so satisfying to open the secondaries and listen to those 12" glasspacks and 4" "echo" chambers do the talking. Truck came from Texas, and was the only one in town with either 12" GP's (18" was smallest available locally) or the 4" x 24" tips at the time. Of course, this was nearly 30 years ago. Besides, I also had a VW diesel for MPG (35+ even with my driving style).
That truck was the inspiration for dad's 390 build. His couldn't quite hang with the 65, thru 2/3, but when I went for 4th (well worn syncro) the C6 gave dad back all he had lost, and then some..... Having the LS axle and much wider rear tires gave me the edge on takeoff, and I'm pretty sure the 200lb rear bumper didn't hurt either. It was made from 6 x 6 x 3/8 angle iron and .250 wall 2" pipe, close to 10ft of each......
Ah, the memories.... Wish I had kept that truck. Also wish my ex hadn't trashed the pics I had of it.

 

Mine didn't have LS, but did have a pretty hefty bumper. It was a nice heavy step bumper that i had modified into a slide-out for the camper. With the camper installed the bumper was far enough back to protect it or provide a step for quick access. It was on two pieces of steel pipe that slid into sockets on the bottom side of the frame. The sockets were about a foot long and the whole thing was designed so the bumper pipes cleared the rear axle when retracted and extended the bumper was still solid enough it wouldn't move. It was retained with two 1/2" steel pins and two 1/2-13 socket head cap screws. When you put the pins in and tightened the allen heads, there was no play of any kind. It probably weighed 250-300 lbs. My son used to take it to Gloucester County and run people with it.

The frame perches from my 300 wouldn't fit the 390, they were too narrow.

 

The maiden voyage was almost without incident. The worst possible thing happened - I rolled the driver's window down and it wouldn't go back up!! So, at 80+ degrees I drove with the windows down - just like I had planned. But, boy is that noisy, especially with the 25 MPH cross/tail/head wind we had.

As for everything else, it went very well. I got 12.6 MPG on the way up, which was almost 100% highway driving. But, I got 11.9 MPG for the around town, test driving by my brother, and the trip back. And, that averages 12.2 MPG. Not too shabby, especially when compared to Dad's truck's 11.0 - 11.5 MPG with far less performance. But, I'm thinking the E'brock 1406 may be even better, so will give it a shot soon.

However, there was one thing that I kept my eye on for the whole trip, and that was the engine temp. While I realize that the truck should have an aftermarket temp gauge, I'm not putting money into Rusty since s/he'll be sold. So, I'm watching the factory gauge, which started the day on the O and ended the day on the M. But, I do have the thermometer in the radiator cap, so stopped a couple of times to check it. The first time was when I got to Dad's house after 110 miles and the gauge was on the R but the radiator was showing 160 degrees while idling. I then turned it off and the radiator went to 190 over a few minute period. On the way home, with outdoor temp up in the 80's, the gauge got to the high side of M, but the radiator was at 175.

I'm thinking that it must have a 190/192 degree 'stat in it, and that everything is OK. The radiator is a very new HD all-aluminum unit, so I'm pretty sure it has the cooling capacity. So, it seems to me that it just takes quite a while to fully get to its top temp, but that it is working correctly.

And, some observations on the exhaust. Someone at the GTG said it is LOUD. I think that was Chris. But, it is starting to grow on me. And, for the record if someone is reading this years later, it is a single Flowmaster 40 with dual tail pipes, which end with 3" sections that are cut at 45 degrees and exit behind the tires. Here's the deal. At idle it sounds mean. At 35 it isn't bad. At 45, in 4th btw, it is the loudest, but even then it isn't all that loud. By 55 the exhaust isn't heard inside the cab, with or without the windows being down. So, as I think about what to put on Dad's truck, it seems logical to put this system on and the single exhaust from Dad's on cRusty. Won't cost anything and I can change it later if I want to.

Thoughts, y'all?

 

351M/400 engines are prone to running a bit warm, especially around town. The water pump passages don't always line up correctly with the front of the engine.
A die grinder and carbide bit come in handy for "porting" the water pump, just can't do much to the plate and block, or coolant can leak into the oil.

 

Oh yeah, as for the exhaust, do it. If you later don't like it, you can change around then. A freer flowing exhaust is much needed, when the engine makes more power.

 

We stretched his/her legs out on country road coming back from the hardware store. I felt the power fall off when we went fron 2nd to 3rd. cRusty felt pretty good , but , that gear change left a little something to be desired. It wasnt a missed gear the motor just didnt have the oomph to keep running strong at the lower end of 3rd. It could have been 3rd to 4th though.

 

Not sure I'll do anything unless there seems to be a problem later. May change to a 180 degree 'stat first if it acts warm this summer.

Yikes! That "country road" was Country Road, and the speed limit is 35 on part and 25 on the rest. If you wound it up in 2nd you'd have been doing 35 when you hit 3rd. Surely that's the case as 3rd takes you to 60+.

 

Yea I like that Flowmaster 40 single in/dual out also. Had one on the 97 4.2 I used to own, sounded great especially considering it was a V6. But think mine was a 40 Delta or Victor, or something like that.

 

It was probably 2nd to 3rd. We turned the corner and shortly after that I told Jason to get after it and see what the 351M felt like. We may have passed a speed limit sign that said 35mph, but we were going so fast I didnt have time to read it or I would have told him to slow down.

We were the first ones to drive cRusty for a minute. Maybe he/she was just a little cold still.

 

I'm thinking that you should swap the exhaust. As you said... If you don't like it you can always swap'em back.

 

After yesterday's drive I pulled the plugs today and ran the leak-down tests. Here are the plugs, with them laid out just as they came from the engine. IOW, #1 is on lower left.


As you can see, 7 are basically dark tan, so probably running a bit rich. But, #5 is almost black, so it is either very rich or maybe burning oil?

And, below are the leak-down test results. Looks like #2 has an exhaust valve that is leaking, although not badly. But, the loss to the sump on all of them was more then expected. Having said that, I'm using a very small orifice in the tester so it is very sensitive. I looked at the tests I did on the Explorer after it was overheated and Rusty is in much better shape. However, it looks to me like it burned ~1 pint of oil on the 260 mile drive yesterday. But, I don't know what oil is in there as I haven't yet changed it, so need to do that and drive it some more before deciding what I think about it.

Thoughts?

 

Good data Gary.

Do you have any idea how long those plugs have been in there?
#5 doesn't look 'fluffy'...
New plugs would have been more telling, given that you have reset the carb.

With oxygenated fuel nothing reads the same as it would with pure hydrocarbon gasoline.

 

No idea how long the plugs have been in there, but they are rusted on the outside. And, they were in there tight. In fact, I had to get my 3/8" breakover to get them loose, and I even had to slap it to break a couple of them loose. I may put a new set of plugs in - I wonder what a slightly hotter plug would do? But, you are right that #5 doesn't have the same look the others do as there isn't any insulator showing through, and it much darker.

As for fuel, I'm running true gasoline. The station closest to me has no ethanol so that's where I fill up. However, the fill up in KS wasn't. And, btw, I did run Sea Foam in the first tank of the run so there would have been some left for the return trip. Also, the idle has settle down nicely. Still running the screws 1/4 turn open, but I might check that again to see if it would like something different now.

 

I installed the Edelbrock 1406 today. Didn't even pull the cover. All I did was put a barbed fitting on the rear for the PCV hose and check out the fuel hose that was on it. Glad I did that since it was packed with dirt. Solid.

However, I did do some work on the throttle linkage. The problem has been that with the Edelbrock intake manifold the throttle bracket had the linkage too far forward, especially for the Holley, so the first half of the pedal travel did nothing and all the movement was in the last half. However, it was opening the throttle fully. I compared the two carbs and while the Holley needed the bracket to move back about an inch, the Edelbrock only needed it back 1/2" or so.

Since I want to be able to put the Holley back on I decided to set the linkage up to be just right for the Edelbrock, which will mean the Holley's throttle will be better than it was but not perfect. So, I put the bracket in the band saw and cut it off sorta in the middle and tack welded a 1/8" piece of strap on the bottom. Then I mounted that on the manifold, put the other piece as well as the throttle cable on, moved things around until I got it where I wanted it, and clamped it. Back to the vise and a few welds later and I had a revised bracket, as shown in the attached photo. It isn't pretty, but the idea was to see how it worked first and pretty it up later. And, given how the throttle felt I'd say it is ready for prettification.

So, how did the 1406 do? Very well! But, there were some differences between it and the Holley. Here are my thoughts from an afternoon's drive, with no data points, just feel:

• Starting Warm: With the Holley the engine started when you turned the key, but with the E'brock it cranks a bit before starting.
• Idle: The Holley didn't have a truly "stable" idle as it seemed to be a bit different from time to time, and the idle mix screws didn't seem to work quite right. However, the 1406 has exactly the same idle each time, and the idle screws gave me complete control as I could kill the engine by closing either screw. Further, it seems, and I stress SEEMS, like the exhaust is quieter at idle with the E'brock. Is that possible? Or am I just getting used to it?
• Take Off: Seeming a tie here as both do quite well from a stop.
• Part Throttle: The E'brock seems a bit more "crisp" as the engine does just what you ask of it. The Holley seems to blubber at slow speeds while the E'brock doesn't do that, although I do get an odd miss or dropout with it every once in a while.
• Full Throttle: The E'brock doesn't seem to have the punch the Holley has. But, I'm not sure the secondaries opened, although I gave them several opportunities. So, I'll have to check that out. However, the engine does run really well at WOT with the E'brock, just not quite as good as with the Holley - I THINK.

I'll have to take Rusty to KS next week to see Dorothy (Dad) and see how the mileage is. And, I need to use Dynolicious with both carbs to see what the engine's output is. But, I can drive it this way for a while and see what I think.