I have a 1973 F-100 that has a 351 2BBL Cleveland in it. I'm planning on buying a rebuilt 1970-74 2 BBL Cleveland that is stock with 8.5 to 1 pistons.

I can't find a spec sheet for horsepower/ torque for the 1970-74 Clevelands. If you have a link please provide. If not what do you think the horsepower of that 8.5 to 1 stock 2BBL Cleveland will be? It will be bored to about 20 over.

 

I had a Cougar that I bought new in 1970, it had the 351C 2bbl and as I recall it was rated at 250 HP. Remember though, this was gross horsepower at the flywheel. A couple of years later they switched to net horsepower ratings with a coresponding drop in horsepower.

 

Do you remember the compression ratio on that one?

 

I think the 1970 351 had 9.5 to 1 ratios. My guess is an 8.5 compression ratio is going to be about 170 horsepower on the stock 351 Cleveland.

What is the best way to boost the horsepower in the rebuild without killing the gas milage?

 

It's funny, I don't remember the comp ratio of the 2bbl. but I remember the comp ratio in the 4bbl., it was 11.0:1. Your guess of 9.5 on the 2bbl is probably a good guess.
As for performance and mileage, just use good engine building procedures. If the comp is down, get it up to around 9-9.5:1. Use the 2bbl heads, the ports on the 4bbl heads are too big for a mild street engine. A cam with high lift and mild duration and overlap. Headers with free flowing dual exhausts. Small 4bbl (600cfm) and a good aluminum intake. Get a roller timing chain that you can index and run it either straight up or 2 degrees advanced. And top it off with a good ignition system.
Also, rebuild the heads for unleaded fuel, hard exhaust seats and stainless steel exhaust valves.

 

I didn't think Ford put Cleavers in trucks did they? Is this one swapped in from a car maybe?

 

I'm guessing it's swapped in. In '73 it would have been a 360 from the factory. F's didn't have a 351 until the 351M in '77.

 

That's right. It is not the original motor. The Cleveland I have in my truck is a 1972 that came out of Grand Torino.

I found a spec sheet and the 1974 Cleveland had 8.6 to 1 ratio and 160 horsepower reading, so I'm guessing a build to stock with 8.5 to 1's will be about that, but that is net horsepower as you mentioned above.

My guess is gross horsepower on an 8.6 or 8.5 will be about 200. I'll need a bit more for that, so I'll probably raise the compression a bit or put in a better cam. I'll be happy with 225 to 250 horse. It is just a work truck. Thank you all.