Good day all. I am pondering a power plant for my 77 F250 SC 2WD.

Earlier this summer when tuning the carb with my vacuum gauge, diagnostics says I had bad rings. Since then I have noticed it uses oil, but no major leaks. It also has very little power.

So, now i am thinking of what to do. I can do a rebuild on the 400, but to do it right, everything machined, cam, lifters, rocker, possible bore, longer piston arms, alternator upgrade, headers and etc. This is gonna cost several thousand dollars.

The other option is to then do a diesel conversion, probably a Cummins. Looking at stock specs, the 6bt has much better torque than say a 4bt, but there is alot more modding to do. The 4bt fits better but has half the torque.

From my limited reading on the 4bt, I would need at least an overdrive trans, because stock it doesn't like higher rpm's..

The main purpose of this truck is to pull our camper. I plan to keep it for a long time, so putting money into it is not a bad investment, but like everyone, money is tight.

Just wanting opinions from you all.

Thanks for the read.

 

A 460 is a better "buy" than a rebuilt 400... more and better aftermarket support and the HP/TQ to dollar spent ratio is a better return.

A stock long block + headers, rebuilt heads, mild, port matching, 4V intake & carb, and a mild cam, and 380 HP and TQ is very realistic on a $2500 budget.

For your info: Budget Big Block 460

 

Just locating a 4 or 6bt motor and trans that is ready to drop in is going to be $$$, getting one that is due a rebuild or some kind of repair is going to be a little less $.

Putting it in is going to be a $ deal, but since you are spending $ one way or the other, might as well go all in right? How long can the truck be down? It is not a over night swap ya know?

But if $ is that tight, do a mild overhaul/rebuild and no headers on the 400 and not a major barn burner build. That would be a quicker turn around I do believe cause you already have the 400. Once the machine shop gets it, you might not be that bad off?

 

Dam, that reminds me, I have a 429, or had a 429 at my inlaws. Already had the heads gone through, but it has been sitting in my in laws barn for like 17 years, might of gotten scrapped. Need to check. Block was in great shape, no lip in cylinder walls. Man, can't believe I forgot about that.

Was doing a rekey on a bank foreclosure, found 3 engines in the garage. Asked the realtor about them and she said please take them. Got a 302, a 352 and a 429. Sold the 302 and 352 and started rebuilding the 429 for a "future" project. One I didn't have yet.

 

Setting for 17 years.... unless it was prepped for storage, it will probably need something, they always do.

429 has some torque, and goes in easier cheaper than a diesel.

 

Plus you could put a ZF5 5 speed trans in .. Plenty of those out there for 2wd 460's at a reasonable cost .. Only a little bit of work to put in the hydraulic clutch and pedal setup .. IMO if your going to be hauling worth the effort

 

The 4bt is usually around 110 HP. Even with a strong torque curve not enough for towing. The 6bt is expensive... to buy and adapt. I'd either rebuild the 400 with good parts from Tim Meyer or the 429. Either should do really well towing. Even my dead stock 400 and 4.10's does pretty well with 6,500 lb.

 

As stated above a 6bt is an expensive proposition. For a good idea what it takes read my thread below. The 460 is a great engine and a good option. The only downside is the mileage sucks.

 

2X ... and it's a bolt in for your truck. I just pulled a 460/C6 from a '77 F-250 sCab Camper Special to put into my '76 F-100 as soon as I finish my current project. Be aware, though, that this beast will operate in the 10-12 MPG range.
There is virtually no end to the power that can be gotten from this engine. To explore those extremities, browse the 460 Ford Forum.

 

Ambitious?

The Supercharger Store

 

Hmmmmmmmm
I like it.