261 Jobmaster engine id
 

Trying to confirm what motor I have:

PO says its a '54 261.
Head has four side screws holding valve cover in place (not 2 on top like earlier 235), front breather cap a Fenton dual exhaust manifold.

Block casting number, right side, aft of fuel pump is:
3759365

Stamped number on flat machined block boss, near front of starter is:
F3I7L

Inline website says block casting is 1959 2 ton truck 261 motor.

Can anyone confirm 261 and year?
What is the F3I7L number (engine serial number?)
How can I id head (235 vs 261)?

Thanks, Maynard

Re: 261 Jobmaster engine id
 

What's casting # on the head? An "848" at the end means it's a 235 head, and will give you higher compression.

Re: 261 Jobmaster engine id
 

Thanks.

Head casting # is 3886850.

Motor runs good. Sounds healthy. No leaks detected but seems to "use" a 1/2 quart of oil about every 150 miles.

Re: 261 Jobmaster engine id
 

How long since it has been ran regulary? When I got my 64 Chevelle it was smoker for the first month I drove it daily, then the rings seated and I drove it about 60K more. If you watch any of the vintage shows on TV most of the trailer queens and museum pieces that do not get driven much smoke too.

Inliners.org has lots of info on the straight 6 and 8 motors.

Re: 261 Jobmaster engine id
 

58-62, 261
Block possibilities
3739365
37369717
3769925
Head
3836850

Don't put a 235 head on it

Re: 261 Jobmaster engine id
 

Thanks. Sounds like I have a 1959 261 with 261 head. It hasn't been run regularly for several years, at least the last 5 years. I'll change oil again and pamper it for a while to see if it slows oil burn.

Thanks.