found a straight six sitting in a storage container and don't know how to tell the ci's-hoping it's a 300. can anyone help?

 

Welcome to FTE

1965/74, the 240 & 300 I-6's used the same block, so the only way to tell which is which is by measuring the stroke.

240: 3.18" / 300: 3.98" / These engines have the intake/exhaust manifolds on the right (passenger) side.

But it may not be a 240 or 300, it could be a 144/170/200/215/223/250 or 262.

The 215/223/262's have the intake/exhaust manifolds on the left (drivers) side.

 

whats the technique for measuring the stroke? thanks for the welcome and reply by the way. dont have photos yet but I'm building a 65 4wd. I'm putting on running gear from a 78 bronco. Got the front end, ps box and new steering column on and I'm on to the rear end (shortening the wheel base while I'm at it to fit a stepside short box. I wanted to trade out the 3 speed for an auto and keep the 300 thats in it, but found what I hope is a 300 already attached to a c4 or c6 (another I have to identify). So far so good considering I know nothing- just kinda dove in. so needless to say any knowledge is greatly appreciated and needed!

 

Since the 240 looks identical the the 300, how do you know the engine that's in the truck now is a 300? The 240 was standard equipment, the 300 was optional.

The engine code is the 4th digit of the VIN, and while not an absolute after 45 years...

1965: J = 240 1V I-6 / B = 300 1V 1-6.

1978/79: The tilt wheel feature was an option on F100/350's and Bronco's.

Does the column from the Bronco have it? Don't look for a separate lever to operate the tilt wheel, because there isn't one.

If you have a tilt wheel, it's operated by the turn signal handle, press it forward = BOING!

C4 = 11 trans pan bolt holes / FMX = 14 trans pan bolt holes / C6 = 17 trans pan bolt holes, The C6 pan has a large notch in it, sorta looks like Utah.

The FMX was only used in 1973/77 F350's w/a 300. The first year FoMoCo offered a 300/C6 combo was 1978.

 

a BIG HELLO TO ALL OVER THERE IN THE US!
this is my first time here........and I am amazed to date with all the information availiable.

Been researching my newly aquired 350 truck-DUELLY/FLATBED/TRAY for the past 4 weeks.......

These are the Australian specs for it- not USA!

ACCORDING TO THE DATA PLATE ON THE FIREWALL:
December 1971 built truck-
serial prefix: AG3 JMC
SERIAL NUMBER 10549D
SIDO 735738
MODEL 73121
PAINT U
TRIM K
ENGINE NUMBER: AG3JMC10549

engine : D
TRANS: 4


FORD Australia refernce parts book shows that a 1972 f350 has the same front grille as mine: ie 12 GRILLE openings
FORD Australia refernce parts book shows that a 1972 f350 did not come out with a 300ci
FORD Australia refernce parts book shows that a 1971 f350 came out with a 300ci or 240ci
FORD Australia refernce parts book shows that THE CODE FOR A 1971 AND 1972 ENGINE D= 240CI E= 300CI

I HAVE BEEN TOLD BY THE PREVIOUS OWNER THAT THE TRUCK HAS A
300CI IN IT???????

THE D ON THE DATA PLATE IS THROWING ME OFF..........
BECAUSE D= 240CI HERE IN AUSTRALIAN REFERNCE MATERIAL
E = 300CI FOR 1971 TO 1973 HERE IN AUSTRALIA
HOWEVER, I HAVE READ THAT D IN THE USA IS INFACT FOR 300CI???

THE TRUCK WAS OBVIOUSLY PARTIALLY ASSEMBLED OVER IN THE
US/CANADA? THEN TOTALLY ASSEMBLED OVER HERE IN AUSTRALIA AT THE FORD PLANT FOR AUSTRALIAN SPECIFICATIONS.

I AM THINKING THAT PERHAPS I MAY NOT HAVE A 300CI AFTERALL?
OR PERHAPS THE ORIGINAL OWNER DECIDED TO PUT IN A 300 CI AT SOME TIME?
OR PERHAPS THE D ON THE DATA PLATE ACTUALLY IS REFERRING TO THE USA CODE FOR ENGINES , IE D IS FOR 300CI

THE TRUCK IS ALL ORIGINAL WITH 2 OWNERS, I HAVE THE ORIGINAL OWNERS MANUAL(SALES BOOK) THAT WAS GIVEN TO THE ORIGINAL OWNER- CONFIRMING THE DETAILS ON THE DATA PLATE ON THE FIREWALL.

I AM ACTUALLY THINKING THAT PERHAPS WHEN THE TRUCK WAS BEING BUILT.........DECEMBER 1971.............THAT PERHAPS THE 300 CI WAS PUT IN AS A REQUEST FROM THE OWNER???????
THE TRUCK WAS FIRST REGISTERED IN 1972........MARCH

SO I HAVE CONCLUDED ITS A 1971 TRUCK ACCORDING TO THE DATA PLATE (73121), (BUT IT HAS A GRILLE FROM 1972 MODELS)
YET IT HAS A 300CI ENGINE AVAILIABLE IN 1971 MODELS BUT NOT 1972 MODELS. AND WAS FIRST REGISTERED IN MARCH 1972.

I REALLY NEED TO VERIFY IF THE ENGINE IS A 300CI TO PUT ALL THIS TO
A REST? ANYONE WHO CAN HELP ME IDENTIFY THE ENGINE CODE? OR BLOCK CODE OR ANYTHING THAT ACTUALLY IDENTIFIES THE ENGINE AS BEING A 300 CI OR 240 CI IS WHAT I ACTUALLY NEED.

I THINK THE MAN FOR THIS JOB IS NUMBERDUMMY???????? I HAVE READ HIS THREADS AND HIS KNOWLEDGE IS INCREDIBLE?????

BUT IF ANYONE AT ALL CAN HELP I WOULD BE GREATLY APPRECIATIVE.

CLAUDE FROM DOWNUNDER!