LWB driveshaft 6cyl vs v-8 length

[Suicide-D]

I am wondering if the driveshaft is the same length between a 6 cylinder and a v-8.

I am contemplating putting my 355 in the LWB and putting a different motor in the 71 when it gets ready.

I have a straight 6 with a TH350 short tail in the 70 LWB now, with a 2 piece driveshaft.

Can I still use this driveshaft with the V8 in the V8 position? (i'm thinking no...)

I don't want to put it in the 6-cyl position... just no room behind the dizzy.

I want to get all this covered (aquire another driveshaft) before I go swapping stuff

Thanks,