Blakes73

All sorted now, hinge pivot boxes welded.in, bonnet on and gas rams fitted. It's a reasonable fit for now and lots of scope/play to get a really good fit. Thanks for everyone's help with this

Just a quick update. I went back to the previous owner who had a spare chasis. This was included in the original deal but I didn't have space on the car trailer. I brought the chassis home for reference and had a friend make me some hinge pivot boxes. Next steps is to offer up and fit this weekend. I also bolted on the body, this fitted perfectly everywhere but the front out riggers. These have been replaced but clearly without properly measuring, they bite currently sat approximately 20mm too far forward. These are going to have to come off so I've purchased replacements from the club shop. So it's body off and engine out, body back on bolt up out riggers, tack in place, body back off and seam weld. These things are sent to try us !!

Thats a lovely looking motor.

Paul, That's a great idea reference lateral alignment. It's also good to know that your hinge boxes match the dimensions on the diagram I posted, it puts the issue to bed, I'm now confident that the aftermarket hinge boxes have just been poorly mounted (approximately 40mm too low). Shouldn't be too much of a problem with the jig you described keeping things right laterally and a bonnet laid in place for vertical reference. Thanks once again, I'll let you know how I get on. Regards~ Steve

Thanks for taking the time to do this. It's interesting to see the difference in apertures in terms of both shape and elongation. There must have been a few variants, either that or variants of aftermarket parts. Regards ~ Steve

I still wouldn't mind a measurement level off the underside of the crossmember to the horizontal section of the pivot box. If you have a look at my photo above you'll see mine measures 145mm and the chasis diagram I posted shows 184 to 187mm, it would be nice with a reference of an actual vehicle. Regards~ Steve

Paul and Kevin, thanks so much for your input and thanks once again Paul, for taking the time to take the photographs and put together the detailed responses. I've come to the conclusion that someone has mounted the bonnet hinge boxes incorrectly onto the chassis cross member. I'm going to remove the boxes and tidy up the cross member. Once that's done (noting the lateral spacing measurements) I'll sit the bonnet (new heritage bonnet with 911150, 911107 & 08 attached) and line the scuttle, sills and door gaps up and then prop the bonnet in place. I'll then attach (probably new) bolt boxes to the bonnet vis 911107 7 08 and tack in place, I'll also make sure the lower valances, lower panel and bumper all line up too. All sounds simple in theory, the practice may be another matter. Regards~ Steve

The bonnet hinge boxes on the crossmember look completely different from the ones on mine. A photo with dims as you suggest would be a great help when you get a moment. Thanks again, Steve

Thanks so much for your help and your time. Steve

Hi Paul, That's my quandary I'm not sure if they're the correct MK3 boxes or they've just been fitted badly. That's the only diagram I could find of a chasis with hinge boxes. All the others seem to be the more conventional hinge type

Apologies, I meant to attach the tech drawing of the Spitfire chassis. Its measurement No. 46 on the drawing that has me confused.

Hi Paul, sorry I didn't get straight back to you, I been busy with work. I've found a tech drawing of a late spitfire that has the bonnet hinge boxes so I'm assuming this will be the same as the GT6 Mk3. I've taken a measurement from the underside of the front crossmember to the top of the bonnet box. This measures 145mm, looking at the chassis drawing this should be 185mm if the drawing is relevant. I've attached images, hopefully you'll see what I mean. I've currently got the bonnet propped at the front and the gaps at the scuttle and sills are somewhere close so I'm thinking it must be the bonnet boxes? The bonnet arms currently sit way too high and too far back towards the engine.

Hi Paul, I appreciate that this was some time ago but if you wouldn't mind I could do with some pointers on this subject. I need to replace the bonnet hinge boxes on my MK3, the previous owner has replaced them and had the chassis powder coated but clearly hadn't checked the bonnet fit (I purchased the car with a new heritage bonnet not fitted, I'm starting to understand why now). The bonnet boxes are new but looking at the fit and some dimensions I found, they're about 35mm low. Any information you could provide would be gretly appreciated. Regards~

I'm new to the forum and club, I've recently acquired a 73 GT6 so have just read the thread start to finish. Looking good and cracking work so far, I'll be watching with interest.