help! 75 2F engine vs 78 2F - differences? (1 Viewer)

[petermac]

Ok, I guessed that the engine I had rebuilt to replace my 78 2F was a 79, but I just checked the produciton date stamp on the DS block and it's a 75. What are the differences between the 75 and 78 and is one year preferable over the other for a rebuild? I know that my 78 had flat top pistons and the rebuilt 75 has domed/arch top pistons. I know this fact because the rebuilt engine was delivered to me with a cracked head that was subsequently replaced at the builder's expense - although it took them two tries to get a head that fit, the first one they sent was an incompatible year and didn't match the block - the pistons jammed on the head. I'm starting to wonder whether the head block combo that I have now is actually a good match, albeit the engine does run. Can anyone tell me how to date the head? The build is done and was paid for up front, so it's pretty much water under the bridge but I thought I was buying (and paying for) a later year (78) rebuilt engine. Also, all the engine ancillaries were swapped direct from the 78 onto the 75 (I was lead to believe the engine was a 78) and it's taken many trips to the shop to try and get it to run right. Problems seem to be stemming from the carb (rebuilt 78 aisan) but I'm wondering if the later year carb or distributer or any other components on the 75 block and who-know-what year head are also causing problems due to compatibility issues. ANy insight greatly appreciated

 

[petescoffee]

Someone else will have to post up woth the specific differences as I did not think there was difference in the block and head of a 1975 or 1978.
Does your block have 2F stamped on it?
1974 was the end of the F but could of still shown up in a early 1975 car.
From 1975 to 1978 I always though the differences are in the ignition and carburation.

 

[petermac]

2f 018790 stamped on block PS above starter. 50417 stamped on block DS under manifold. Definitely a 2F if I read it right.

 

[petermac]

Numbers stamped on top of head (DS) are 60052 and 1104. ANy guesses as to the year?

 

[Advent]

78 should be domed pistons.

The differences are mainly ignition and carburetor, some vacuum lines as well.

If it were me, I'd take the '75 block back and make them get me another one. A sure fire way to fail inspection around here is to have an engine with the block and emissions equipment being different years, and also just plain having an older block in a newer vehicle. You might not have that problem, but it's something to think about.

 

[FJ40Jim]

Numbers stamped on top of head (DS) are 60052 and 1104. ANy guesses as to the year?

Head #60052 would be mid-late 1960's F engine.

A 1977-1980 USA 2F head is a 61031.

E-76 USA 2F head is #61030

75-77? canada head is 61020.

Notice that 2F parts are usually 61xxx.
F engine parts are usually 60xxx.

 

[andrewfarmer]

If you've got a 2F block with F head - keep it - you'll have better compression.
Rockers are oiling ok?

60034 is a non-US 1.5F head (flat top pistons)

What are the 'running right' problems you are haivng?
What octane petrol are you using?

 

[Corbet]

somewhere around 78 or 79 is when the blocks got drilled for power steering I think. So a 75 would not be compatable with a factory PS set up. Some one chime up if my dates are wrong.

 

[petermac]

If you've got a 2F block with F head - keep it - you'll have better compression.
Rockers are oiling ok?

60034 is a non-US 1.5F head (flat top pistons)

What are the 'running right' problems you are haivng?
What octane petrol are you using?

Engine has not idled well since rebuild. Progressively, I had to run the engine with the choke closed more and more just to keep an idle. NO vacuum leaks! I had the carb rebuilt along with engine (same outfit - took them three tries to get me the right/working carb, but that's another story). Many, many months later, the latest "rebuilt carb" (#4) arrived, had it installed and the engine will idle (+-600rpm), albeit a bit roughly with some dieseling. Could be the setup but mechanic thinks not and is very reliable with good rep locally - not a cruiser expert though. Also spark plug knock under heavy load, running low-octane feul. Knocking reduced running high octane. Engine has Downey "mid-range" horsepower cam and ceramic coated tri-y header. Was promised engine would run normally with "moderate" cam, no need for high octane feul. Promised alot of things! To the company's credit (the one that did the rebuild work), they've continued to try and fix the problems, on their schedule mind you. On the bright side, the engine pulls well, has good power when it's running. I can't believe though that I might be running a 75 2F block with a 60's F head and I was told I would get a rebuilt 78 2F. That's f%*%ed up!!! What to do though. They've got my money and they're 3500 km away. I just wanted my damn truck to run well. Thanks to all who've replied with info/insight.

 

[petermac]

No emissions concerns. Canadian truck, no smog equipment, no testing in my province on vehicles this old.

 

[petermac]

If you've got a 2F block with F head - keep it - you'll have better compression.
Rockers are oiling ok?

How do I know if the rockers are oiling ok?

 

[Tahoe Dude]

From what i have seen a 2f block and head match up from 75 to late 79 as i purchased a 79 block with round water holes from spector to install stock power steering79 still had domed pistons and large combustion chambers ,what altitude are you ,and and what advance are you runing ,total and inital mine wont ping yet at 6225 ft yet

 

[andrewfarmer]

How do I know if the rockers are oiling ok?

pull rocker cover and start it. Oil should come out of the small hole on top of the rockers.

Have you done a compression test? That will give you an idea on what the compression is. If it's the combo I think, you'll need hioctane for sure.

From my experience, an idle problem is not usually a 'hard' motor prob, but a bolt on part...

What's your vacuum at idle?
Have you checked the brake booster for a vacuum leak?
Valves adjusted ok?

Points OK? - is the dissy cam lightly greased?

Vacuum on dissy connected to correct ports on carb? (try disconnect and plug at carb...)

 

[honk]

Petermac,
This sounds like a nightmare! The first thing to do is stop all interaction with the people who've done this to you. You're unlikely ever to get satisfaction and life is too short to continue this story any longer. It's gone too long as it is. Write off all losses and start again with whatever pieces are usable.

If you are unable to disassemble your engine and go through it from scratch to see that it will work correctly then use resources from this site to find someone near you to help. Go to the 'international' forum down below this one and explain your plight. There are many Canadians hanging around in there who are both willing and honest enough to get you set in a right direction.