Alright, I just tossed the old radiator that was sitting in my truck for over 22 years. I decided to get the larger radiator (max. cooling) and flushed the six. It's time to either rebuild or replace the six. It has severe blowbacks coming from the valve covers. It is also starting to lose oil pressure once it heats up. Thus, I think that it's about time to replace or rebuild. What do you all think? I can get a 300 long block for about $925 or take it in and get the thing rebuilt. What's better?

ALSO...

I'd like to upgrade the ignition system, will an MSD ignition work on my 81 ford six? Has anyone done it?

 

Personally I would rebuild the original 300, unless of course the block, crank, and head are worn beyond their tolerances. Rebuilding an engine yourself has it's advantages, you are able to upgrade to better internal components; i.e. torqueyer cams, chrome piston rings, heavier duty bearings, high volume oil pumps, all kinds of aftermarket parts to make your 300 more powerful and last longer. But then again buying a remanufactured long block has one major advantage over everything, a warranty. Most companies that rebuild engines require your old engine as a core. The new engines are ususally bench run and dyno tested before they come to you. Keep in mind reman engines are rebuilt to factory standards and the warranty could become void if you open the engine to add or change internal components. Which way you go really depends on what you are doing with the truck.

 

Hmm, warranty does sound good. I was also going to replace the stock exhaust manifold and the intake too. I've never rebuilt an engine before, only a lawnmower engine. What about the MSD ignition? I was looking at another distributor that has the coil on the distributor. Does anyone have that?

 

coil on the distributer? That is Chevy HEI, and they are expensive to get one that fits a ford. No reason to do it. I have MSD, its great. It is a 6a
There is nothing wrong with duraspark however

 

Yep, there was actually one that was for Fords 6's and 8's. I freaked out when I seen them. I'll try to find the link to them. Back to the MSD.... did you change out the Duraspark or connect to it? Did you change the coil too?

 

If you do a search you will found several horror stories about mail order and parts store engines. If you decide to have the existing engine rebuilt take it to a reputable local rebuilder. They are typically much more concerned with customer satisfaction because they don't want to compromise their integrity and lose business. Large scale rebuilders don't have to worry about that.

 

This is true I didn't even think to mention that, yes be careful who you buy your engine through.

 

I was looking at a local machine/engine shop. They wanted to sell me a long block ($975, with core core) and Autozone's longblock ($925 with core ($250)). BUT, what if I decide to bore out the six? How much can I take out with out compromsing the walls? I'm not looking for a super huge pistions, but I'd like to make it into a 300+ Cu In. Any suggestions?

 

Your best off planning to remove only what's needed to clean up and true the cylinders. Plan head work, cam, intake, exhaust...all BETTER sources of power than gaining a couple of CC's. My local Napa guy told me that most mass rebuild shops (in CA) have a bunch of people who barely know what they're doing rebuilding these "remanufactured" blocks - with a few know hows checking on them. How is the price so cheap? Because the labor and materials are cheap. I think everyone has a story about a "remanufactured" part that they bought "new" from somewhere that failed (ie altenator & steering gear for me). Sure the store glady replaces it, but you're the one stuck with removing and replacing what you just put in. I think that there are some reputable mass shops that do a decent job, but none around me. Jasper's web page is impressive, but I'd still want to check out there facility prior to making a purchase - but that's just me. Check out the price at Jasper and then ask your self how the other guys do it for so much less? Warranty is only as good as the person / company backing it up. Sometimes? small fry tend to be ignored when it comes to big business....my .02

 

60 over is only a 309, I wouldn't wqorry about overboring much. I tossed the duraspark and ran just the msd, but you can use both, if you wanted to for some reason. I think the biggest gains for a six is just getting a little more air/fuel in there. I know it "doesn't work" to just throw a bigger card and intake manifold on a motor, but the stock 6 only has about a 150 cfm carb, and it has pretty big ports in the head.

I have a 272/27? crane cam. The exhaust side has more lift and duration, but I don't remember how much more. I also have a dual port offenhauser intak manifold and a 500 cfm carb. I know the carb is too big, but they are cheaper then the 390cfm that is recommended. I also have a dual outlet heddman header. The power may not be what big block V8 guys are looking for, but the difference is amazing. Before I used to just drive it around floored most of the time. With a light trailer (8X10 with a couple of dirtbikes on it and gear) I could get around OK, but uphill freeway onramps where a little challenging. Now I can't even tell it is backl there. The change is truely amazing.

 

You can't bore out the 6 too much because the walls aren't all that thick. I think i read that you can get about 10 cubes from it or so. Max bore is around .060

 

Mine is bored .040 over, running an RV cam, stock carb and intake, stock exh manifold. I found my most noticeable power gains from Accel coil, K&N airfilter, cutting off the cats, and installing a Flowmaster 40 series muffler. Pulls very strong still suffers a little on the long hills, probably because of the 1bbl carb and intake.

 

I wasted the time & money on that ONCE - never again. I'd recommend swapping in a late-model EFI 4.9L. It's the best thing I ever did to mine. The hardest part was the wiring, but it's lasted ~300Kmi (after the wreck that SENT it to the junkyard where I bought it) with no problems.

 

I thought of converting to EFI but cost stopped me. I am partial to carbs myself. And if my 84 doesn't quite have enough guts to get the job done (has not happened yet) I'll just bust out my 77 F250, if that doesn't do it nothing will!

 

My EFI conversion cost me a grand total of $1300 including air filter, Y-pipe, gas tank, pump, fuel lines, belt, hoses, oil, anti-freeze, and PSF. It took ~5 days working alone.