Torque Converter and drive plate depth

[RamblerRob]

I'm putting together my engine (4.3l v6) and Transmission (ZF4hp22) with the kit from marks 4wd.
According to Ashcrofts website I need to have the 'feet' of my torque converter at 51mm depth from the mating face of my bellhousing to ensure the correct seating of the torque converter and not damaging the oil pump upon installation.
Now when I measure the placement of my driveplate after installing the conversion components I find that it sits about 46mm back from the back of the adapter plate that will mate with the bellhousing. I'm currently only using the drive plate and buttress ring, though I could add in the flexplate as well (this would irritate me aesthetically as I have a fly wheel to engage with the starter and it seems dumb to have an additional flexplate/ring gear just as a spacer :/))

I'm certain I need to do some sort of spacing on this but my question is this:
Does anyone have any inkling on what kind of 'play' would be acceptable in this measurement? I wouldnt want to make it too tight or too loose.

Thanks
Rob

[RamblerRob]

I read on a chev forum that the play should be between an 8th and 16th of an inch so 2-3mm. Still leaving me with a few mm extra. As much as I hate to do it it seems like if i put in the flexplate and driveplate with the buttress ring on the correct side of the driveplate it would put me about bang on. Easily testable except I dont actually have the flexplate :/

[bhoult]

Are you certain you have the TC seated when taking this measurement? It is an art to get the TC all the way on the ZF, they usually stop about 10-12mm out and then you have to "english" them into place.

[RamblerRob]

I haven't got to that part yet. I'm taking the measurement from ashcroft where the torque converter should be once seated correctly, 51mm. and the actual measurement of where the drive plate sits from the mating face of the engine adapter plate

[bhoult]

I'll have to research the Mark's kit. I don't understand why they would have a flywheel in the mix. Is there no other way to balance the 4.3? I suppose you could add a 5mm spacer to the back of the adapter instead of using the flex plate, but that begs the question of what you bolt the torque converter to. Are there tabs on the flywheel to which to bolt the feet of the torque converter? Sorry to ask questions instead of answering one.

[RamblerRob]

Well the Chev flywheel is there to engage with the starter as normal. The drive plate is there to bolt to the crank adapter and the torque converter feet. As for the flex plate.. I'm not sure it's anything more than a spacer if it's intended to be there at all

[bhoult]

Ok - that makes since. I've read the spec on the Mark's site a few times over the year but always thought they were including the flywheel commentary if you were converting from a 3.5 with a manual to a 4.3 v6, rather than the ZF.