Well, I've gotten 7 years out of my questionable block with cylinder cracks and sleeves in 3 cylinders but am now seeing low compression on the center cylinders on the passenger side and water on the dipstick. I replaced the head gasket but am still down on power. I don't think I can handle another search for a block (I went through 7 last time before I found the current one). Has anyone converted to say a 300 -6? This is in a F5, so high torque at low rpm is great. Is there a conversion kit to keep the original transmission? Any thoughts would be appreciated.

 

Howdy,

Welcome aboard!

The 300 would be an excellent engine for an F5! (there were 60-70's F-600s that came with the 300.....It was my second choice if I didn't use the 292 in my F600!)

You will not be able to use the original trans though without using an adapter (which is not available I think)

BUT, if you can find a 300 out of a 90's donor truck, you could use the ZF5 5 speed/OD trans that would also probably be in the same truck!

OR, you could use an E4OD like I am using in mine.

If you use either transmission, you will also need to find a tail-mounted parking-brake for it.

My E4OD came out of a 94 F-450 Superduty and the original owner swapped it out to install a ZF 5 speed, but he kept the parking brake so I had to scrounge one!

The 300 was mated to the E4OD in a LOT of trucks and if you used it you could probably also use the EFI 300 + the ECM which would control the EFI and E4OD that was in the 90's trucks.

The OD will be a great addition to your REALLY low ratio rear axle (mine is a 6.80:1 ratio!)

Do you have any pictures? We LOVE pictures!

Regards,


Rick

 

Rick,

Thank you for the information. I like the idea of the 5 speed ZF. I've got the 2 speed axle so it would make it quite versatile. How difficult is it to add the drum for the parking brake?

What about motor and crossmember mounts?

I am also curious about the speedometer. I would like to keep the original with it's mini-transmission for keeping the correct speed with the axle.

My truck is stock except for the seatbelts and an electric fuel pump, and I would like to remain as stock as possible. I realize an EFI engine means converting to 12V, but that would be a good upgrade.

 

Mike,
If you want to maintain the transmission,drum brake etc, do a search for adapters of ? to ford. I would start with Speedway. I ran a nailhead Buick V8 thru a stock drive train in my F-1 for years (bought it that way). I would not recommend that now , however many sbc were installed replacing flatheads for years. I don't know about other engines-just haven't looked. In the case of a sbc I think that it will be basically a bolt in.

Edit: I checked Speedway and the only one that I saw was sbc. There should be others from past times. Hopefully someone else will chime in.
I checked Wilcap. The only one that they sell bolting to "newer" engines is the sbc one. I also noted, per Wilcap, that it only was used up thru 1 1/2 ton ford trucks. That does not make sense to me. Am I missing something? I am not a big truck guy.

 

Not sure where you are located but if your heart can take it there's an 8BA posted in the ads right now that appears to be in good running condition and the price is good. It's in Northeast PA. I'm rebuilding 8BA now and got lucky on the block on first try.

 

Bill: I'm familiar with the Speedway conversion for the SBC, but something just doesn't seem right about putting a GM engine in this nice old Ford, even though I have a SBC in the garage under a tarp . . . I don't understand Wilcap's comment of being good only through 1.5 ton; I'm pretty sure the same flathead was used in the entire range.

"Appears to be in good running condition" is scary. I've seen several that actually ran well but had serious cracks in the heads around the valves.

I love flatheads, but it is so hard to find a good one. I think the love affair is over!

MG

 

Mike,
I am afraid that if you want to stay all ford you will either be making a custom mount/bellhousing to marry a different ford engine to the flathead transmission or you will have to change out your transmission, transmission mounts, clutch and brake pedals etc,etc. Nothing bolt in to my knowledge. One of the problems with Ford engines unlike GM, they had a number of different bolting patterns for engine to trans. The sbc adapter fits many engines for many years. I am a Ford guy. The only GM that I every owned is the Buick nailhead that came to me in my F-1 and the current stroked 383 and 700R4 currently in my F-1.

 

That's a Beautiful truck!

The 300 would be a great addition to it and with the ZF5 & 2-speed, it would also be pretty nice!

The ZF has a 0.80:1 OD........... I assume you have the 8.11/5.83:1 2-speed and 8.25-20 tires?

With the 5.83:1 and 8.25-20 tires, you have approx 19" rolling radius.
(I have 9.00-20's on mine and I have nearly 40" diameter tires!)

That would give you approx 530 rear wheel RPM @60mph

530rpm x 5.83 = approx 3100 RPM and with the OD 3100 x 0.80 = 2480

Running a 300 at 2500 RPM is right where it wants to be!


Yes, you would need to come up with different mounts. (the newer transmissions do not have bell-housing mounts, although you could probably FAB them.

I changed mine to side engine mounts and added a rear cross-member.

You could build your own parking brake probably but there is already a good brake assembly that bolts right onto a ZF or an E4OD

If you don't want to fool with EFI, there's a LOT of 300's out there with carburetors.

Not sure what to tell you about the Speedo. I was worrying about the same problem but I am just going to use modern gages in a 55Ford-looking panel and a GPS speedometer.