differences between '71 and '72 gt?

[kndlindsey]

Okay, I am brand new to opels, just brought home my first two last Sunday. One is a '71 and one is a '72 and no, i dont know which is which till i match the vins to the titles, lol.

one is bright yellow and one used to be bright purple but has faded to a grey/purple.

I keep telling my husband i swear the yellow one is bigger as in taller with a shorter nose, the purple one looks lower to the ground, shorter and looks like it has a much longer nose.

He says it's the difference in paint colors, is it?

[spdkilz02]

i would say that ur husband is right...the body panels are all interchangable from year to year...

[yellaopelgt]

Unless one has had body damage and had somthing spliced in, they are excactlty the same size. Might be that one has sagging springs or shocks but thats the norm. Paint wouldnt really tell the year, and purple wasnt a factory color so its been repainted. Only true way would be from the VIN # but...........those can be changed as well, so make sure they all jive, one on dash, under hood i think, and there might be one on the doors(whitch are switched up quite often as well as motors)BTW the numbers on the motors DONT coincide to the VIN # so forget that plan of attack. There are a few numbers in some odd spots and my memory fails me but I'm sure someone will chime in and let you know where to look.
Congrats. and have fun!
Joe

[RallyBob]

Originally Posted by kndlindsey I keep telling my husband i swear the yellow one is bigger as in taller with a shorter nose, the purple one looks lower to the ground, shorter and looks like it has a much longer nose.

It could be something as simple as one having shorter tires, and perhaps a set of lowering springs installed as well. That makes a remarkable difference in perceived 'sleekness' of design.

Bob

[kndlindsey]

I kinda figured that they were identical as to part exchanges and it had to be the color, just blows my mind how much color, tires, etc. can trick your eye as to what it sees. I have to stop and stare at them everytime i pull in the driveway. Maybe i need to move them so they aren't side by side and it will quit messing with my head, lol.

When we brought them home the garage was full and has to be resituated before i can get them in. The "garage" was acutally a pig barn at one point, then converted to use to service semis, there is lots of room, in fact Dave said if you parked them all in sideways instead of front to back you could fit 8 cars in there. But right now my sons '80 chevy lowrider and daves '67 chevelle are right in the middle and need to come out to make room at the back for the opels.

Dave asked me where in the yard I wanted them(we live on 12 acres, 3 of it being yard "proper" around the house and outbuildings) and I told him, where I could see them from a window anytime i wanted till it warmed up or we got them in the garage! I look several times a day and get a big grin on my face every time i do.

[gtjames]

I'm pretty sure the '72 had pop out side rear windows, did the '71 have pop out windows?

[opelnut10]

If it is a 71 it doesn't have the two extra bolt holding the front of the head to the front cover. also if you take off the valve cover the year is cast into the head between the oil return holes, unless of course the head or engine has been changed. If it has been repainted purple there is no telling what has been done to it because that person was not well, lol.

[GTJIM]

Both should have Chassis numbers starting with "77" - the model designation for the GT in both years. The earlier '69s and '70s started with "93" or "94" and the later '73s had "OY07" or some such (and "77" as well .... so Nobody tells us!).
The 1972 production year started with Chassis No. 77-2560567 so the 1971 one will have a number before this and the 1972 a number bigger than this.
However ... they could have been initally titled at any time after construction as they had to be shipped to the US of A; sold and titled ... after they were actually built.

[69whitegt]

So, really there is no way to tell if the engine in your GT is the original?

[Bo Mows]

Not really, unless you have original sale papers. Yeah Right! At least if the block and head have the same year as the body, you have a chance they may have been rebuilt instead of replaced.

Bo

[namba209]

Originally Posted by 69whitegt So, really there is no way to tell if the engine in your GT is the original?

Not really, Opel did not have matching numbers for the engine/tranny/rear-ends, like the US manfacturers did. Which is not really a bad thing, if you think about it. If you change any of those components it does not degrade the vehicle in any way, unless you went from an early hi-comp engine to a low comp in an early Opel.

[kwilford]

Originally Posted by kndlindsey Okay, I am brand new to Opels, just brought home my first two last Sunday. One is a '71 and one is a '72 and no, i don't know which is which till i match the vins to the titles, lol.

Read the .pdf file at:
http://www.opelgt.com/forums/showpos...04&postcount=8
on the thread:
http://www.opelgt.com/forums/gt/5403-need-help-identifying-gt-year-model.html

Originally Posted by gtjames I'm pretty sure the '72 had pop out side rear windows, did the '71 have pop out windows?

Nope, the change from fixed to pop-out rear windows was
between the '70 and '71 model year (mid-'70 build date IIRC)

Originally Posted by opelnut10 If it is a 71 it doesn't have the two extra bolt holding the front of the head to the front cover.

Maybe. The change to the 12 bolt head was during the '72 model year, but from what I have read, it was late in the model year, so perhaps a summer build date.

HTH

[spdkilz02]

Originally Posted by kwilford Maybe. The change to the 12 bolt head was during the '72 model year, but from what I have read, it was late in the model year, so perhaps a summer build date. HTH

yeah cuz i had a 72 and the engine and head was a 72 and it was only the 10 bolt style...

[neuttron]

Originally Posted by gtjames I'm pretty sure the '72 had pop out side rear windows, did the '71 have pop out windows?

My 71 does have.

[opelnut10]

All the GT's that were imported to the US had the swing out quarters after the 1970 model. The GT/J that was sold in europe and Canada did not, they had fixed windows. As far as the 10 or 12 bolt head afew of the early 72 models had the 10 bolt and those are 8.5 to 1 compression ratio with a semi-dished piston, when they changed to the 12 bolt head they went to the full dish piston and compression went to 8.0 to 1.

[kwilford]

Originally Posted by opelnut10 All the GT's that were imported to the US had the swing out quarters after the 1970 model. The GT/J that was sold in europe and Canada did not, they had fixed windows.

That would be news to about 20 million Canadians back then! The GT/J was never imported into Canada. Some may have made it here by being brought back by Canadian Military Personnel on tour in Germany. All of our GT's were U.S. specification. Swing rear windows and all after 1970.

Originally Posted by opelnut10 As far as the 10 or 12 bolt head a few of the early 72 models had the 10 bolt and those are 8.5 to 1 compression ratio with a semi-dished piston, when they changed to the 12 bolt head they went to the full dish piston and compression went to 8.0 to 1.

The switch to the lower compression ratio engine for North American Opels was at the beginning of the '71 model year (about August 1970 build date). It had the "dished" piston (and hydraulic lifters and four bearing cam) with an advertised 7.6:1 CR versus the older flat-top pistons' 9.0:1 (which, by the way, still had valve reliefs). RallyBob will tell you that both were optimistic, as were HP rating. There was not a semi-dished and full-dished piston, although the last few years (with the 12 bolt head), '73 to '75, had a slightly different dish design, but the same 7.6:1 CR.

JM2CW

[tekenaar]

Originally Posted by opelnut10 All the GT's that were imported to the US had the swing out quarters after the 1970 model. The GT/J that was sold in europe and Canada did not, they had fixed windows. As far as the 10 or 12 bolt head afew of the early 72 models had the 10 bolt and those are 8.5 to 1 compression ratio with a semi-dished piston, when they changed to the 12 bolt head they went to the full dish piston and compression went to 8.0 to 1.

Actually, 'flat top' piston engines were 'factory' rated at 9.0:1 CR whereas the 'dished' piston engines were rated at 7.6:1 CR.

Here's a link for US Opel Models 1958 - 1967.

Here's a link for US Opel Models 1968 - 1971.

Here's a link for US Opel Models 1972 - 1975.

And here's a link for All Models Drivetrain Guide 1964 - 1975.