Zag,
Thanks for the advice and for being objective. I have no intention of disposing of the original parts (ie the 1500/T7 4 speed the Spitfire is a different situation as it came to me with no motor and the non overdrive 4 speed). As to selling it or getting into a situation in which it becomes necessary??? who could say? The car was originally purchased for my daughter to drive when she is old enough (that was when she was 4 now she is almost 11 I have some time) I have enjoyed being her driver. The Triumph 1500 has great low end torque and revs nicely. It really is not that under powered. All this really came about as a result of wanting an overdrive (the one out of the Spitfire) or a 5 speed box. On the freeway it is turning 4000 rpm |removethispart|@70 mph. That is just not acceptable. But...(always have to have one of those) the o/d Spit box runs around $1100 for a good one and the 5 speed conversion from Frontline was over $1500 a few years ago and has gone up since then mostly due to the sinking dollar creating an increasingly negative exchange rate. I don't even check it any more, it's just too painful.
So, that brings me to where I currenly find myself, if I'm going to spend that much money to get a top gear under 1:1, I might as well upgrade the motor as well and that brought me to the 1600 Zuki as the most likely candidate to fit without body modifications and not to alter the weight balance. Being that the 16v version is essentially no different externally from the 8v, why not use that?
So, now the difficult part, where do I find this 1300 DOHC w/ crank fire ignition? Also I assume this is a distributorless ignition so no worries about clearance to the back or anything hitting the firewall? Already planned on different springs.
As for the Spitfire, I have an R180 (3.89?) waiting to be removed from a 1st gen Maxima the 810 based Maxima, however, I have some reservations about this rear end as the rear brakes are common only to that year and the parking brake cable is impossible to find. But, yes, I had contemplated the Z car rear suspension. I understand Subaru used a similar rear end which was also IRS, the main difference being the Subaru came out of the factory with limited slip. Is this correct?
I would like to take a moment to thank everyone for their input and advice. You have given me much to think about and sent me in directions I certainly would not have taken on my own.
John