View Full Version : pinion angle question
Pops
May 13th, 2015, 09:13 PM
If a 1965 half ton swb now has a inline six with a saginaw tranny, would that throw off the pinion angle if the truck sets stock (still has 8 leafs each side, coil fronts). I ask because I believe the "65 GMC's only came with v6's and a Muncie trans.
A lot of folks write about angle probs causing vibration probs at lower speeds, but that doesn't make sense to me unless you lower or raise a truck.
David R Leifheit
May 14th, 2015, 08:34 PM
If a 1965 half ton swb now has a inline six with a saginaw tranny, would that throw off the pinion angle if the truck sets stock (still has 8 leafs each side, coil fronts). I ask because I believe the "65 GMC's only came with v6's and a Muncie trans.
A lot of folks write about angle probs causing vibration probs at lower speeds, but that doesn't make sense to me unless you lower or raise a truck.
Okay, here is the question.
Does your VIN start with an "I" ?
If so, the inline is stock.
Since the 1965 GMC factory manual has a section on the inline 6, there is every possibility that it is stock.
Pops
May 14th, 2015, 08:50 PM
Come to think of it, I believe the 230 inline six was available. I too saw it in a '64 shop manual. I believe the Chevy 250 inline was base in 1966 GMC's.
Thanks for feedback.
Perhaps others may know if the 250 was available in the last runs of the 65's.
Onuma
May 20th, 2015, 01:01 AM
Perhaps others may know if the 250 was available in the last runs of the 65's.
According to Jolly's page, there are at least two 1965s with inline 6, 250 cid engines. Is that what you were asking?
http://6066gmcguy.com/GMC-vin-list-65.html
Pops
May 20th, 2015, 04:35 AM
Yes that is the question I was asking. I haven't read Jolly's write up about 250's in the 1965 but I have seen several ads showing 250's were new in GMC for 1966.
My frame part number is 1965 according to other threads. My 250 is casted as Sept 1965 which is correct for a Sept built 1966. To make a long story short, I'm ruling out vibration issue which could be related to pinion angle, engine aligment, motor mounts, drive shaft components, etc. So, if 250 was used in 65 and 66 there shouldn't be any engine alignment concerns.
Update: yoke, ujoints, and drive shaft balancing in progress. I will update with news on vibration.
Thanks for response. Like I said, this is the first time Ive heard anyone say that 250 were used in '65 gmc's.
Onuma
May 20th, 2015, 05:05 AM
I just happened to be looking there as I browsed this thread. Fortunate timing! The 250 was probably only in a few 1965 GMCs, very late in the model year. Seems much more common in the 1966 trucks.
Jolly has an abundance of info which I've found useful since I got my '66.
bigblockv6
May 20th, 2015, 05:09 AM
That's very likely because in 66 only the 250 was supposed to be the only inline six offered yet I've seen 292's in 66 models from the factory.
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