Posted By: RapidRobert
original tire size/dia '68 GTX - 02/09/12 01:15 AM
My 1st Mopar. pretty sure 14's & Magnum?? wheels. Thank you for your time.
original tire size/dia '68 GTX
Posted By: moparcanuk
Re: original tire size/dia '68 GTX - 02/09/12 02:14 AM
I'm pretty sure they were F70/14 with a 26.4" diameter.
Posted By: moparfan53
Re: original tire size/dia '68 GTX - 02/09/12 02:27 AM
...unless it is a hemi of course! 
Here is a link to the 68 data book tire page.
http://www.hamtramck-historical.com/images/dealerships/DealershipDataBook/1968/68_Belvedere0026.jpg
Posted By: RapidRobert
Re: original tire size/dia '68 GTX - 02/09/12 02:36 AM
no Hemi but it was a convertible . Thanks guys for the info. What's going on is I have a 3.91 going into an A body & I remem how buzzed the GTX 440 was w the 4.10's & wanting to get a rough handle on how much larger dia tires I need now to slow down the A body project rpm some which is going to be a subjective decision EDIT Canuk it was your other thread that got me thinking about this & I wanted to confirm the size (was over 35 yrs ago). The big Rocky Manginelli swap meet in Lincoln is coming up in a month & prob can score some 15" ralleys and early A's can take a large dia tire at least in the rear wheelwell
. Thanks guys for the info. What's going on is I have a 3.91 going into an A body & I remem how buzzed the GTX 440 was w the 4.10's & wanting to get a rough handle on how much larger dia tires I need now to slow down the A body project rpm some which is going to be a subjective decision EDIT Canuk it was your other thread that got me thinking about this & I wanted to confirm the size (was over 35 yrs ago). The big Rocky Manginelli swap meet in Lincoln is coming up in a month & prob can score some 15" ralleys and early A's can take a large dia tire at least in the rear wheelwell
Posted By: phantomx
Re: original tire size/dia '68 GTX - 02/09/12 02:40 AM
Why not decide on the tire you want to run and then gear it for the rpm you want to cruise?
Travis..
Travis..
Posted By: RapidRobert
Re: original tire size/dia '68 GTX - 02/09/12 02:45 AM
because I have no wheels/tires on hand other than 14" ralleys in front & I have a good 742 3.91 sure grip which ain't going nowhere
Posted By: lewtot184
Re: original tire size/dia '68 GTX - 02/09/12 03:17 AM
'68 440 gtx would have had an f70x14 redline. a hemi would have had f70x15.
Posted By: moparcanuk
Re: original tire size/dia '68 GTX - 02/09/12 04:19 AM
Bob,
A 3.91 gear with 28" diameter tires will give you the equivalent of a 3.44 gear. Pretty nice for all around driving. The larger the tire, the higher the gearing you will end up with.
A 3.91 gear with 28" diameter tires will give you the equivalent of a 3.44 gear. Pretty nice for all around driving. The larger the tire, the higher the gearing you will end up with.
Posted By: RapidRobert
Re: original tire size/dia '68 GTX - 02/09/12 03:34 PM
Quote:Exactly. Thanks guys!
A 3.91 gear with 28" diameter tires will give you the equivalent of a 3.44 gear. Pretty nice for all around driving.