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 Height Difference in a 2 Bolt Frontsub & Single Bolt

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 Posted: Jul 20, 2018 12:18PM
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US
I'm pulling this one back up now that I sorted out my log in as just one of you... There is indeed a small height difference if you look at the top of the spring 'towers'.  The upper stamped plate that is welded on (that contains the huge 3/4-16 thread for the MK4 bolts) is about 1/4 inch shorter than the earlier ones (in my case, the 'wet' frame from my 66 Cooper S). 

I had the two side by side and decided to adapt the very nice late MK4 front sub frame into my MK1.  The height difference equals the thickness of the 'sandwich' rubber mounts of the MK4, so I made some solid aluminum spacers just thick enough to keep from contacting the steering rack with the sub frame (happens if you try to install with no spacers), and some top plates to spread the load of the enormous 3/4 inch bolts.  The standard MK4 bolts are shouldered to allow the mounts to flex and limit crushing the bulk head.  I'm using big grade 8 bolts and supporting the area in place of the two 5/16-24 bolts that hold the early sub frame to the body.

Certainly can't be any weaker!  I'll post a video when I finish making the lower mounts. Can't easily use the solid MK4 rear mounts as the mounting to the early floor is a bit different.  There is a large stamped (and VERY hard to crush- I tried flattening it!) dimple protruding where the mounts must go, so I'm fabricating some small solid mounts to my floor.

Why bother?  Availability of an excellent MK4 frame with an engine steady in the front cross-member.  I never trusted those 5 inch bolts with 5/16" thread that hold the early ones!  An opportunity to improve my resto-mod further as I have the front end and engine all in bits.  Curiosity about the feasibility of the swap... there are certainly far more decent MK4 sub frames available, and it should be stronger and even more solid that the early ones!

 Posted: Jun 27, 2018 09:28AM
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US
I"ve got an automatic frame if you want to take measurements Jim.  It's at work.

 Posted: Jun 27, 2018 08:38AM
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GB
Quite a height difference from memory, and the bulkhead needs modification too.

 Posted: Jun 27, 2018 06:58AM
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US
Hi, Is there a height difference? Will a single bolt front subframe fit a 2 bolt mini ( of the body would need to be altered to fit the tower bolt ).