96 750 srad motor swap to a 78 kz400

So. not really sure on how im going to do it or what the dimensions are exactly. but my buddy has a 96 750 srad. that he laid over. and I have my 78 kz400 that has been sitting behind my garage gathering rust. so my plan... not completly thought out. but my plan is to put this 750 srad motor in the kz. now again the dimensions are not figured out completely but i have the ability to buy his whole bike for 600 bucks. full bike just needs to be put back together. but i want the vintage type of look with modern power. what are the thoughts on this? im good with sportbikes. just stepping foot into the old school. im 22 if you can get an idea where im coming from. i want a project. ( other then my 07 zx10) which is never ending anyway. but i was thinking 750 sportbike inline 4 cyl. in a kz. possibly swapping the inverted forks over. dont tell me to go search the forums bc unlike most ppl ive already read most threads concerning front end swaps. and i kno some leon guy is the guy to go to. leon id like to kno the process of which you do the stem conversion btw. not to steal business. but as a young kid eager to learn a thing or two. this is what im thinking and to be honest havent got to his house to do measurments YET. but im thinking front end swap. with the gsxr front wheel, rotors and calipers. rear end. not sure on clearance or axle sizes. but id like to swap the gsxrs rear wheel to the factory kx 400 swing arm.. bc primarily id like to keep the dual shocks. bc id like to get lower ones to give it a more bobber/ cruzer look. i love the beefed up front ends. and id like to make the braking system more modern as to this is a high rev motor. just looking for as much info as anyone is willing to give me. tell me im crazy... dumb... what ever you got. i just want to go to a show with something ive put together and modified. basically from the ground up. i want ppl to go what the hell is that thing? did that come with that motor? what year is that? what type of bike is it? or sitting at a traffic light and my fellow sportbike riders pull aside look and laugh bc im not sitting on my zx10. and then i pull out and have more balls then they were expecting bc they were expecting an old school bike with "old school power". give me your thoughts. pros. cons. i want to get as much info as possible. things to watch for. basically things i am over looking. again i havent taken kz400 frame dimensions or the gsxr 750 srad engine dimensions yet. my concern its too wide and will sit past the foot pegs. and also if the forks are a pain to do i will stick with factory forks. id like to kno the thought really about the forks bc if they wont work or are a pain i can buy just the motor, rad, harness & componets, guage cluster and exhaust for half the price then buying the wheels, tires, chassis, forks, clip ons etc.

I couldn't read that wall of text, however based on your title, I would recommend you measure everything about 10 times before getting on board there.
I have a 2007 engine going into a 77 1000 frame, and it requires heavy heavy modification.

You are going to need to redo all of the mounts, none will work as the SRAD is a trellis-like mounting system, whereas the KZ is a traditional on-the-frame mount. You need to change your swingarm out or go to a much too small tire. You will need to come up with a alternative fuel supply system, as the stock tank won't accomodate the pump you need, and an inline pump will require modification of the fuel rail. Then we get into the cooling system that the frame is not shaped to accomodate very well either.

... and then theres always the possibility that the engine won't even fit into the frame. I'm working with a 1000 frame which is presumably much larger than the 400, and it is almost an impossible fit, at the very least requires a hand built exhaust and hand built intake.

On the other hand it would make a pretty bad ass bike if you're into that stuff

yes i kno all of the mounts will all need to be fabbed. bc of obviously the mounting variations. gas tank accomidations are what i was thinking. now 96 srad is not fuel injected it is just well 4 carbs. but it has a fuel pump like component in the tank to draw fuel to the carbs. im not looking to use the air box. too big to tall . just gonna look into puttin filters on the intakes. or make my own sidemount intake. again judging by the width of the motor. thats what i was looking for. good deal im not the only moron looking to put a modern high rev motor in a old school bike. i see alot of mods and things for a kz1000 but not many for a 400.. and thanks thats what i was thinking to as far as frame sizes. 400 presumaly smaller then 1000 frame. im just kinda going with it. trying to get ideas/problems im gonna run into. thanks for your input. sorry for the wall of text. im just excited actually. i wanna get rollin on this.

Ah, cool on the carbs, that helps out a lot as you can just jam pods on there if necessary and just re-jet.

Just go over the measurements many many times. If I could have used a 400 frame I would have (or even a CB550 I would have preferred), theres just no way on the size though. Even with the big old 1000 frame its like solving a rubicks cube getting the engine inside the frame, and even then it is within 1 inch of contacting the front of the frame, STVs are about 1.5" below upper frame/gas tank bar.

What you could do which would solve your frame size issues is convert it to partial trellis design. I hemmed and hawed about doing this myself, chopping the rails about 6" below the neck, bending outward then down the side joining about 8" forward of the shifter area. I really wanted to keep the frame as close to stock as possible though so I maintained the more difficult approach.

...but if you go that route be sure your welding abilities are top notch and if you don't have an engineering background, talk to a professional about what bracing would be required to regain your rigidity.

That engine will pretzel your frame. Way to much power for a frame designed for roughly 25 HP. I would fix the 750 it would be cheaper and much easier.

You can do eeeetttt!
WTFN?
Worst case your gonna fail on frame mods...what's a 400 frame go for , like a 100 bucks? Start again.
Best smiles per miles i ever built was a CR500 (race 2 stroke MX) in a CBX 250 (4 stroke single commuter.) That bike cracked,twisted and generally fell apart with regularity but holy shit was it fun!
Leave the 400 badges on though.

Boyracer does have a point. I have had some of the most fun on some POS I patched together and had to keep repairing.

128 hp liquid cooled engine in a KZ400 frame; for sure you have your work cut out for you! I once shoehorned a BSA 500 twin engine into a BSA 350 single frame and drove it for about 9 years. What I learned is that everything must change to do such a conversion (frame cut & stretched, brake pedal, footpegs, rear wheel/sprocket width, electrical system, chain rubbed frame, the list goes on and on). In other words - you can do it! But don't be a dummy like me; as mentioned ealier, measure everything and plan everything in advance. And don't forget to brace that frame bigtime or it will turn into spaghetti.

SRAD
www.motorcyclespecs.co.za/model/suzu/suzuki_gsxr750%2096.htm

Hey,sounds like an adventure for sure.I would not make it back.I am lookin for set of wheels for my 78 kz400 if you decide they are of no use to you.Original equipment is all the adventure I need,but hard to find.

i just unloaded a low mileage kz400 a few weeks ago,from what i remember of the frame your ideascares the hell out of me! :woohoo:
ive seen what 128hp does to an unbraced 900/1000 frame,couldnt imagine it in your combination! :woohoo:
maybe pick up a cheap kz650 to shove it in,at least the dimensions would be a lot closer and the frame would be more up to the job
if you really want to hot rod your kz400 maybe try shoving an ex500 motor or a dirtbike motor in there

I've got several 1000 frames, I'll give ya' 1 for your project if you would like to start with something a little stronger

Jon

that would be bad ass but ur looking at serious fab work just a big bore kit cams and nitro in a kz1000 dam near turns those frames into pretzels if they arent braced up good