I have a 69 fatsback that I want to cruise with. I want great low end and good highway cruise range (a/c too!!). The car has the 351w now and I was wondering, would upgrading to the 460 be a good choice? I'm look at the cubic inches. I was thinking with the 460, I could go with 3.08 gears and get gas mileage and performance, rather than 3.73+ with the windsor..... Anybody got a suggestion?
460 v 351w
- Thread starter torrie68
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What do you define as good mileage? If you want something in the double digits, don't do the 460. I averaged about 8 mpg with mine. With the 351 I get about 13-15 on the highway with 3:1 gears. You might want to think about going with an overdrive tranny. Then you can run 3.73's with the 351 for good take off and still cruise down the freeway at a decent rpm.
10 MPG with a mild 460 wouldn't be too out of the question, epecially with low numeric gears in the back (which you could do, all the torque would make up for it). What motor you have any parts of right now would probably determine which is cheaper to build, for the majority of parts they're pretty close. For the most potential and bang for the buck though, IMO you can't beat a 385 series, and I say that even being a 351C guy.
WORTH
Dirt-Old 20+Year Member
mustang70 said:
If you keep yur foot out of it the 460 is fine on gas, my73 town car got 15 in town and 19 hyway. With a heavy foot it got 5 in town
if tuned right you can get decent mileage from a 460 powered car, as long as you drive it right. keep i light foot on the throttle and drive it like the cops are following you ALL THE TIME, and you can get 13-15 around town and 18-20 on the road. stomp the throttle once though and you get 5-8!!
ratio411
Founding Member
What you describe would be perfect for a very mild 460 IMO.
You don't describe the need for cornering, the 460 is too heavy.
You want high gears... 3.00s with a 460 is still stump-pullin'.
If you don't go crazy with aftermarket parts, a 460 can be cheap to build. Although I would spring for aluminum heads just to loose a ton of weight. The Lima blocks are VERY heavy engines.
The Stealth is the best intake for this engine from what I have seen... It destroys all others in magazine test after test.
A small vacuum secondary Holley will be fairly efficient.
Headers would be a must. Believe it or not, they increase fuel economy.
Just some food for thought.
Dave
You don't describe the need for cornering, the 460 is too heavy.
You want high gears... 3.00s with a 460 is still stump-pullin'.
If you don't go crazy with aftermarket parts, a 460 can be cheap to build. Although I would spring for aluminum heads just to loose a ton of weight. The Lima blocks are VERY heavy engines.
The Stealth is the best intake for this engine from what I have seen... It destroys all others in magazine test after test.
A small vacuum secondary Holley will be fairly efficient.
Headers would be a must. Believe it or not, they increase fuel economy.
Just some food for thought.
Dave
torrie68 said:
Yes, I had the 3:1's when I was running the 460. I also had a stock cam, intake, and exhaust manifolds. The only performance part I had were the ported heads which were 70 castings. And I had a 600 cfm Holley on it.
I'm not trying to change your mind, just telling it as someone that has doen it.
As for the cornering problems, I never had any, but I'm also running 720 springs in the front with KYB shocks and a 1" sway bar. If you don't have power brakes though, you will need them. There were a couple times I wasn't sure I was going to stop in time.
ratio411
Founding Member
Cornering problems as in road racing.
I got better mileage with a stock 460 than my built 302. It was about the same after a manifold/double pumper swap. (power was way up though)
I had 3.28 gears in mine at first, it was unreal! They broke fairly quickly though, darn 8" rears... After that, I used a 2.79 gear and it never broke, but low end power felt like it took a hit.
I might let you guys know that this was a beater rocket that I put together as a teen. I wouldn't mod in this order or use an 8" with a 460 today.
Dave
I got better mileage with a stock 460 than my built 302. It was about the same after a manifold/double pumper swap. (power was way up though)
I had 3.28 gears in mine at first, it was unreal! They broke fairly quickly though, darn 8" rears... After that, I used a 2.79 gear and it never broke, but low end power felt like it took a hit.
I might let you guys know that this was a beater rocket that I put together as a teen. I wouldn't mod in this order or use an 8" with a 460 today.
Dave
Hack
15 Year Member
I can't help but agree. I've got a 250 I6 if you want mileage from an inexpensive engine.Max Power said:
Also, a modern fuel injected 5.0 would be much more efficient than any carbed older 6 or 8. You can find a 5.0 out there for not a lot of money as well. Grab one out of a Crown Vic, or Grand Marquis.
To me, a 460 is more for radical 1/4 mile racing much more than the street. There are a lot better choices for the street. You want the most modern, light, efficient engine you can afford IMO - if you're trying to maximize both performance and mileage.
Now if you just are looking for a reason to put in a 460 because you've always wanted to do it.. by all means go for it! I'm sure it would be a fun "over the top" build to show off.
Rebuild and stroke the 351W! You can get over 400c.i. out of it and with aluminum heads, good intake,cam, carb you will easily make over 400 h.p. and 400 lb. ft. of torque. Don't go overboard on the heads, cam ,intake and gas mileage will be reasonable. This combo is good for 500 h.p. if mileage isn't a concern, but a milder build will give you over 400 h.p., better torque, and better mileage. Since you don't plan on nitrous or blowers you can save alot by skipping forged cranks, pistons and aftermarket rods; use the stock stuff for a cheaper rebuild. You will also save several hundred lbs. of weight to help with gas consumption.
blown65
Founding Member
mustangdave said:
what he said, Id do a 408 or even a 427 myself. Little less cubes, but weighs less too.
Hack
15 Year Member
This is a great suggestion. Injection gets you a lot of efficiency and some power gains. I'm not so sure about supercharging as a path to economic power, but you seem to want a lot of power. I'm used to running a 250, so your 351 seems quite fast to me.Ronstang said:
Also, going with a 5 or 6 speed manual transmission would gain you gas mileage.
ratio411
Founding Member
Ever try to put a 3' wide engine in a Maverick?Max Power said:
Believe it or not, I have seen pics of 460 conversions!
Talk about fender to fender engine!
Dave
SadbutTrue
Founding Member
Hack said:This is a great suggestion. Injection gets you a lot of efficiency and some power gains. I'm not so sure about supercharging as a path to economic power, but you seem to want a lot of power. I'm used to running a 250, so your 351 seems quite fast to me.
Also, going with a 5 or 6 speed manual transmission would gain you gas mileage.
A lot of the late model guys love SCs because, unless you put your foot in it, the supercharger has little to no effect on the engine, and you get normal gas mileage. Which, in a light(er) car with an EFI 351w, could be decent.
My built 429 gets 10-12mpg as long as I stay out of the gas. The 385 series will drop right in and there is no need to remove shock towers. You may have to go with electric pusher fans for cooling. The 429/460s are torque monsters. There is ssooooo much there it is not even funny.
Build your suspension around the engine and your condering fears wil be non-existent.
Build your suspension around the engine and your condering fears wil be non-existent.
