I decided to post this dyno chart to show a very close comparison of the two engines. Now to make sure everyone is clear on this, these are 2 dyno results done many months from each other. You will see the 460 does make more HP & Torque. But I want to show that they are not that far off. Both flat hyd camshafts. Same dyno. Stock mid to late 70's heads. So if a stock rebuild is what you want, is it worth pulling the 400 to install the 460 and the changes that need to be made.
FYI, I am NOT 400 bias. Just Ford Bias.
OK, go ahead flame me!!

 

I'm going to assume this is gross HP/torque at the crank.

TMI, does the 400 out-torque the 460 below the shown ranges? I've never seen it, but always assumed the 400 had higher torque at 2000RPMs and less than the 460. 400 has a 1/4'' longer stroke than the 460

 

Good info!

 

We start the dyno pulls low enough to see the peak torque and end them just after peak HP. So I can't say for sure about the lower rpm torque.

 

With my F350 I can drive to work and back just fine unloaded without going over 2200RPMs. I'd love to know what kinda torque the V10 is putting out at my usual shift points, but I dont think I have ever seen even one graph that showed that. Its pretty rare I even drive into the rpm band most the dyno graphs show at all (over 3k) unless I'm hauling something. Is there a reason we never see curves that actually start from, well, the start? Atleast yours here is down to 2600 or is that 2500. I can't wait till the day I have money to build my 351M and I sure would like you to do it Tim.

 

Why would anyone flame you?Most people that swap the 351M/400 for the 460 dont know anything about how to make power.Thats why they swap them out.The Modifieds are apart of the cleveland engine family which have an awesome reputation for making power.They are very strong torque motors whose only drawbacks are being built in an age of lowered compression and emissions.You change the cam,raise the compression and advance the timing and your looking at a whole different animal.Its a wonder they ran like they did the way they were choked down from new.The 460s were just as choked down of course but being a little bigger the power loss wasnt as noticeable so theres defineately no excuse for changing out a 400 when they have just as much potential and are just as reliable.

 

Tim what would be your educated guess on fuel economy between the two?

 

Horrible and slightly less horrible.

 

Tim,have you posted this on the 385 series forum?You might get flamed over there!The other posters here are right,this engine has a lot of hidden potencial.

 

My gut tells me the 400 would get better mileage than the 460. But there is not going to be a big spread. I am choosing the 400 because of the smaller displacement and the long stroke.
No I have not posted this n the 460 forum, I didn't want to pick a fight.
I just wanted to share this because of this forum thread.
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i'm a 460 guy, but i wont flame.
i know 400's have lots of potential.

BOTH were originally written off as smogger crap for the most part

BOTH types of engines are enjoying a lot more love and support in the aftermarket as far as parts go.

BOTH are perennial top 10 finishers at the EMC regardless of change in rules.

 

I'm currently working a 400 ford. Just bought new transmission automatic 4speed with manual shift from hughes performance. On the 400 ford I have a set of d2ze CJ heads and was thinking of puttin on 400 motor. Was wanting to put them on something. I like the 400 and like the 460 also. But was considering the 400 because of a little fuel mileage gain. Cam will be hyd rollered. It will be put in a 4x4 1970 air bagged and many other upgrades. Only issue for me is exhaust manifold/header issue. Question is the CJ heads worth the extra hassel. I like my motors to breath and living at 4000' elevation you need all the air you can get. I also play at 9000+elevation. truck will be used for daily driver and occasional towing during hunting season. I live in the rocky mountain region and MPG heads is who I use for most of my ford upgrads and scott main does good work for me. Just curious your input. I know your good at what you do and have my respect. I like it when the old iron runs good. catch you later and keep on building!!