my hollander interchange manuals show diff auto trans for a 4.3 reg cab thn a 4.3 ext cab ,diff 305 reg cab and ext and diff for 350 reg cab and ext cab ,,, u check the motor interchange no diff between reg and ext cab motors same on flywheels and torgue converters no diff reg or ext cab so sounds to me like the distance frm block and trans meet surface to where flywheel bolts on is same for all 4.3's so the converter length whn seated in frnt pump to where bolts to flywheel should be same on all 4.3's ,,,same on the 305 and 350 ,,,so now i got to figure out diff between v6 and v8 trans where it bolts to motor and flywheel
There are no differences between a reg cab and ext cab trannys. In 98, 4L60e's had two different bellhousing arrangement's. One bolt's on, the other is a 1 piece case(like 350s). 4.3 tranny's will bolt right up and work perfectly behind the 305 or the 350's, as long as you use the same type of case that came out of the vehicle. If you change the case type. The difference is in the offset of the flexplate. Converter bolt pattern is the same on all of them. Also, if you change the case type, the mount will sit a little rearward of where is was before.
i've sen 2 diff ones wth removeable bell ,,one is 6 bolt and the other is 7 bolt has the bolt right n the center top and it is 3/4 longer thn the 6 bolt but as long as u use the matching converter its ok ,,,like i said the interchange books say they different
Just because there is a hole there, doesn't mean it has to have a bolt in it. Not all block's have the boss there, some do and not threaded. Believe me when I tell you, I know 4l60e trannys, their converters, and the flexplate that goes with the converter. F body cars had a different input shaft and pump stator (longer) in the trans to work with the different converter they used. On 98 pickup truck's, big or little, blazer or Tahoe, 4.3, 5.0 & 5.7 all use a B-29 converter, that will interchange between all of them. I do it every day.