Hello fellow dent-side owners,

I've been visiting this great site a tremendous amount over the last 4 weeks. Reason being is that I recently purchased a 73 F100 lwb 2wd dent-side. The original owner parked the truck about 2 years ago because he thought that the rear-main seal was dumping oil (which it was). So when I purchased the rig with intentions of replacing the seal and driving truck around with a for sale sign to make a quick flip. Well things don't always work out as they should......

I've since slowly fallen for this truck (bad problem for my wallet), and then the I discovered after pulling the motor to replace the seal that there were more issues at play.

I pulled the oil pan to get to the seal and discovered one of the piston skirts laying in a puddle of oil in the pan. Worried that the cylinder wall maybe scratched to hell, I completely tore the motor down to inspect. Pistons are already at .30 over and the cylinder walls look clean but I'm going to send everything into the machine shop for further inspection.

After tearing the engine down I also discovered that someone has magically upgraded the crank and rods to the 390 setup (yeah for me). My intentions are now to rebuild this FE390 for the sole purpose of driving that truck around town and maybe occasionally pulling a small trailer from time to time. After looking in ebay, amazon, and the internet I've found master rebuild kits that range from $250-$3000.

Can I get some advice on a good reliable rebuild kit that won't brake the bank for my intentions. Also, the headers that came with the truck look damn near homemade and rusted to hell. Any advice on a good set of headers that work for this truck would great too.

Thanks for reading and replying,
Paul

 

Oh the joys of rebuilding an engine. It is like picking out features you want in a girlfriend.

As far as pistons, rings, bearings, etc. most are on par when it comes to quality. Unless going hog wild with the engine, the cheaper parts from a reputable name in the business is good. Clevite bearings, pistons from a good name source, Felpro gaskets. You get the drift?

First off, you really need to decide what you want to do with the engine. If you expect to keep it fairly stock then you certainly may be able to re-use a lot of the components or buy less expensive parts.

If you are going to keep things mostly stock then you are likely going to be re-using the crank and rods as long as there isnt any significant wear or damage.

Piston choice will come down to desired compression ratio and if you wish to run 87 octane or high octane gas. Don't get obsessed about compression though. Going from 9:1 to 10:1 only gets you about 4-5% more power. 9:1 you can probably get away with 87 octane. 10:1 you are almost certainly going to need to be running 91-93.

A nice mild cam upgrade would be nice. Flat tappet cams are cheap! Keep the 0.050" duration under 230 degrees for sure for stock heads and such. Will probably need a very mild spring upgrade. Any bigger of a cam really wont pair well with stock heads or likely your driving needs and gearing.

A good dual plane intake and a 4 barrel carb of 650 maximum to top it off.

Not a header expert, but I am sure there are some out there that fit these trucks and these type engines. 1 1/2" or 1 5/8" primaries is what you want with a 2.5" or 3" collector.

 

2x with reputable brand names.

Fel Pro gaskets

Intake.. go straight for the Edelbrock Performer RPM 7105 and the matching cam & lifter kit (PN 7106).

Double roller timing set. Cloyes or equivalent.

600 to 650 cfm carb with vacuum secondaries for the street. Double pumper if your wallet can handle it. Add a one-inch phenolic spacer to stave off heat and it's worth a few TQ numbers.

Do a DIY gasket-match and runner smoothing using Summit's carbide bits and cartridge rolls. You're not hogging them out.. just cleaning them up for smoother air flow. The first inch of the heads is all it needs

Headers.. Sanderson Headers 3/4 length (PN FF427) is the least headaches. Go for long tubes if you're a glutton for punishment. Dual exhaust using 2.5-inch tubing and free-flowing mufflers.

A few FE links in the Tech Info Compilation for your perusal. Use 'em.

EDIT: Melling oil pump, Edelbrock water pump, CVF pulleys if ya want eye candy, Gates belts, Ford Racing oil pump drive, Pertronix ignition module PN 1281, Autolite plugs, Pertronix plug wires, Shell Rotella T 15w-40 engine oil, 180° thermostat with a 0.125-inch hole drilled on the flange and the hole positioned at 12 o'clock when installed to bleed out the trapped air, and a 14x3-inch open element air cleaner. Yes, keep the PCV valve.

 

X3 on the good parts. I did long tube headers on my pickup it's a 2wd. I will never do again not worth the time or trouble.

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Thank you so much for the advice so far. I'll be posting more questions as I go along with this build. Everyone I know keeps telling me to toss the FE and throw a small block in there, but I refuse to let go of that big steel beast.

So what about the valve seats, should I have them hardened when I get the heads checked out by the machine shop if they aren't already done? I plan on running California diluted 87 octane if I can get away with it.

I'm loving the replies on the parts so far, and since I'm keeping this beast as a daily driver and nothing more than that the list of parts seems to fall in line with everything I've been reading on this forum for rebuilding the 390.

 

Those advising ya to dump the FE are likely just recommending the SBF because that's what they know. The last year of the FE was 1976!!! Perhaps waaaay before you or those advising ya were born!

In my opinion, a 302 is these rigs results in an underpowered pig that can't get out if its own way... a 302 simply doesn't have enough torque and torque is what matters to get these rigs off the line. It might have overall comparable TQ numbers but at what RPM??? Ask them that!

Sure a 302 would get better mileage but hey, I'm getting 16-18 mpg with my '70. The TKO five-speed helps a ton.

 

I would expect the valve seats are already hardened. Unhardened valve seats were only on leaded gasoline engines. Doesn't mean they are for sure though. They won't harden them. You buy hardened ones and have them installed.

Depending on how much head work you need, it may be worthwhile just to bite the bullet and buy a budget set of aluminum heads for probably about $1500-1700 for the pair with springs and valves already installed. You may be putting in over $1000 to have heads decked, new valve seats, valves, etc.

Are you going to have to pass emissions in Cali and put all the smog stuff on it? If so lower compression will help you out. Higher compression ups the NOX emissions.

 

In CA, model years 1975 and older are exempt from emissions. Hence my toys, except the Ferrari 360, are exempt. But hey, it's a Ferrari!

...2x. If reworking the iron heads, sometimes it makes better sense and cost effective to go with aluminum heads. The realized gains are worth it IMO.

 

Make sure you block dosen't have the oil galley to cooling system leak.

 

Awesome, feedback everyone. Thanks again for all the replies. I'll get online in a bit to look at some aluminum heads to price compare against machine work. Thanks.

 

I agree with keeping the FE. I love the dent sides and to me nothing feels and looks right in these trucks except the FE. I have used Comp Cams complete kits over the years with good results. The aluminum intake is a lot lighter and performs great. I'll be following to see where this goes.

 

I agree with HIO above on his intake suggestion.
However I do not agree with his cam/lifter suggestion..... you can do so much better that that.

Good luck.