1979 360 engine
should i just get a 727 ? thanks
You need to do some research on the trans.
The 273 came with a 904 trans. The early years (I think 66 and earlier) transmissions have a smaller pilot on the torque converter than the later ones, so you have to get the proper torque converter with the right diameter nose.
You can install the 727 in the car, it will bolt right in, and the linkages are also in the same location and will work. The 727 is a few inches longer (2'-4') than the 904, so you will have to get the drive shaft shortened and balanced to compensate.
You also have to get the proper torque converter and flex plate set up.
360's are externally balanced, 340's were internally balanced. The torque converters are balanced differently for each one. 360's had balancing weights on the torque converter. 340's were internally balanced also and had no weights on the torque converter. So to tell the difference in a 340 converter compared to a 360 converter, look for the balancing weights. If the converter has balancing weights, then it is for the 360, if it doesn't have the balancing weights, it is for a 340.
B&M makes a special flex plate that is balanced to put the 340 torque converter on the 360. If you find a 340 converter, you can use it with the special B&M flex plate on the 360.
http://www.manciniracing.com/bm1.html
The 65 drive shaft and trans use the trunion, where the 66 and later transmissions use the slip yoke. You may want to consider converting over to the slip yoke with the 727.
However a 904 can be built with heavy duty parts and be able to handle the 360 also, you can decide which way that you want to go. The 904 is lighter, has less drag, and can have a lower first gear ratio to get you off the line faster than the 727. However 727's are a bit stronger with the extra clutch pack over the 904...
