i have a 72 f 250 with a very fresh rebuild aka less than 15 miles on a 360 bored 30 over, a radical cam a 4 barrel edelbrock intake and 600cfm carb. with 4.10 dana 60 rear end and 36" tires and a 4 speed tranny i average about 11mpg. with the truck kicking out 445 horse and 515 torque

 

Not to call BS. But, you need to back those numbers up with something other than an amatuer pass at Desktop Dyno.

A 360 might make 445HP in an extremely radical configuration that is not suitable for a 72 F250.....Unless, you know something I dont know. Which, remains a possibility.

 

And I wasted alot of money on 410's and 453.8's the last 34 years to get those numbers. My parts supplier must think i'm a stupid money tree for them. We took a 453.8 w/T-18, w/23.125" tires to 5,520 RPM's,(3 tachs lowest reading) in a 70 CS. I should of rebuilt a 360 and gone faster.


CJ Zoom....=o&o>......

 

That should of been, 32.125" diameter tire. sorry. CJ Zoom...=o&o>.....

 

well first off i did use desktop dyno as a starter when i started to rebuild the motor but when i finished it i threw it on the water dyno we got at the school im in and those are the numbers at the fly wheel. but im just quoting the dyno machine.. for all i know i could be wrong but i has been used several times and checked with more than one for accuracy it is usual within + or - 5 horse and 15 torque but thats all. so i beleive it to be pretty accurate.

 

Beemer, what rear end ratio were you running?

And was that you that was passing me on the Bay Bridge, or where did you run this?

 

Hey WillyB, that was with 3.54 gears on a 9.72 cr 453 ci engine. The cam started out as a Crane 34391 specs, modified to different specs, (266/284) custom ground. The frame twists, steers to the right and has the aerodynanics of a brick. My friend is thinking lower gears, overdrive unit, (taller gearing overall) laughing gas or 6 lbs of centrifugal boost. I would go to a 482" (425 HP/ 600 TQ) mild street for decent fuel mileage and long life. Before I forget, we use the San Mateo bridge for testing without traffic, 12' above seal level, no jet corrections needed. You should see the surprise on BMW or Porsche's owners faces when the "brick" eats them. Now a 482 w/mpi
sounds like a winner. I got that warm feeling thinking again (dream).

Carl....=o&o>....

 

Loaded...unloaded...it doesn't matter. With my '67 I pull about 9mpg regardless of throttle input.

 

A shade under 150 MPH - That would be a ride to remember!

 

Been there many times (12+) it's common to reach 148 (minus tire growth) with the right conditions, new rubber, lowered truck with suspension tricks. Lap and shoulder belt, I'm safe at speed without traffic that with. This animal will get 12 mpg at 62 mph. I welded on Spintech mufflers 3" with X cross like done on my 414. I may change my Edelbrock RPM's (5510) as they drone on my 414" vs Spintechs (8332/8333 series).

Carl....=o&o>....

 

You boys need to take a cold shower, yall done got toooooo worked up, and have crossed over.


John

 

arctic, how do you know you're getting 11mpg if you've only got 15 miles on the motor? 1 gal est is not very accurate. Just playin'.....

 

Gearvendor overdrives....how are they installed, and how are they activated? A truck I am looking at has one...the owner said the automatic function of the OD doesn't work so they activate it manually with a foot pedal....can someone better describe?

 

with my 72 ford I only get 10 mpg but on long trips I get about 14 mpg