safe FE revs...

[bigjake34452]

hey guys, i dont know anything about the FE engines, i will be getting a 73 f100 with either a 360 or 390, i was wondering, what do each of these engines rev out to safely?

[19674x4]

dont go much 5 grand. they were made to produce power at low rpm's and you will notice the torque curve drop at or around 5k.

[bigjake34452]

thanks man, o and one more thing i forgot to mention, is there a way to tell the difference between the 2 by the outside just looking at it?

[j41385]

Nope. You have to measure the stroke.

[averagef250]

I don't think you can get a stock truck FE to 5000 if you try. They don't make any power past 4000.

[19674x4]

i get my 352 to 5k but thats about it. 2nd gear pinned. after that it loses power and powerband drops

[Redcap]

I don't think you can get a stock truck FE to 5000 if you try. They don't make any power past 4000.

I don't think my FE has ever seen over 3500. No reason to wind it that tight.

[Ronnie1972]

Hey Jake,

One of the GREAT "Did you know" tips describes using a dowel rod with the engine at TDC. Stick a dowel rod in the first cylinder, measure to some point on the outside (a reference point like lip of valve cover or something). Now take it out and stick it in the 4th. Measure to some point (same point) on the outside. Measure the distance between the two and voila, you've verified if it's a 360 or 390. Exact stroke is somewhere in here. Worked great for me.

[James72]

well here's a question, why is that my '72 crew diffs are geard like a tractor with a granny low 1st aswell? These FE's make low end power so why not taller gears? I can't do over 55mph without it sounding like it's trying to escape from under the hood. Then low range 1st is too slow for rock crawling even

BTW, it's stock except for the engine

[ToughOldFord]

Granny low is for serious loads, don't use it if you're not hauling anything.

Don't understand your gear problem though, even when I had my 4.10s I cruised at 75mph with no issue. Maybe you just have a lot of engine noise?

[James72]

Granny low is for serious loads, don't use it if you're not hauling anything.

Don't understand your gear problem though, even when I had my 4.10s I cruised at 75mph with no issue. Maybe you just have a lot of engine noise?

That could be, Id like to put a tach on it. But it sure seem to rev high and lose power around 50mph.

[RedneckTexan]

well here's a question, why is that my '72 crew diffs are geard like a tractor with a granny low 1st aswell? These FE's make low end power so why not taller gears? I can't do over 55mph without it sounding like it's trying to escape from under the hood. Then low range 1st is too slow for rock crawling even

BTW, it's stock except for the engine

That's what makes the bumpsides so strong! Tractor gears in the diffs (4.10-1 for me) and the 6.68-1 for first gear in the tranny makes these trucks the kings of haulin! I can't tell you how many thousands of pounds I've loaded into my 68 F-350, but I can tell you she has NEVER strained, no matter how big the load!

[Chaseman]

Yeah I have a pretty steep gravel driveway and to avoid messing up the

gravel I stop at the bottom , put it in low and just idle up. Sometimes I forget

the mail so I just get out while it's going up and run to the mail box then get

back to the truck before it gets to the top. Or if it's flat and me and my friend

are bucking hay I stick in low and get out and let the truck drive itself while

we buck hay

Btw it has the NP435 with 4:11 gears

[RedneckTexan]

Yeah I have a pretty steep gravel driveway and to avoid messing up the

gravel I stop at the bottom , put it in low and just idle up. Sometimes I forget

the mail so I just get out while it's going up and run to the mail box then get

back to the truck before it gets to the top. Or if it's flat and me and my friend

are bucking hay I stick in low and get out and let the truck drive itself while

we buck hay

Btw it has the NP435 with 4:11 gears

I've done that a time or two BTW, my truck has the same set-up.

[19674x4]

that makes three of us.