iscellaneousThe driveshaft I used is the stock Mazda unit, with the yoke from a Ford driveshaft (mine came from an ‘85 LTD II patrol car) that is the same diameter as the Mazda. Any good driveshaft shop should be able to do this cheaply (including balancing). The speedometer cable was made by a local speedometer shop. You will have to give them information on gear ratios and tire diameters in order for them to make a new cable. The exhaust I used consists of MAC 1 5/8“ equal length shorty headers (BBK and Hooker both make headers that will fit as well) for the ‘85 -’93 Mustang. I also used the 2 1/2“ H-pipe (that goes from the headers back under the car) from MAC (also for the Mustang). You could get the same thing with catalytic converters from them or a number of sources for emissions purposes. The rear exhaust was made for me at a local muffler shop. First I hung the mufflers (Flowmaster 2 chamber) and made a pair of templates from 5/8“ electrical conduit, which I had the muffler shop match. The exhaust is hung from the stock Mazda location in the rear. In order to fit the mufflers, it was necessary to trim away some of the heat shield where the stock mufflers went (but leave some between the mufflers and the fuel tank).
The radiator mount needs to be redone so that the radiator sits vertically, instead of at an angle. This is accomplished by first removing the transverse round crossmember that mounts the horns and oil cooler. Then a pie-shaped slice is taken out of the sides of the radiator mount. The mount is then rotated to vertical and re-welded. the stock radiator then can be remounted, or the dimensions can be used to have a custom radiator made (my choice is Griffin, which is what I’m using now. Griffin Part number #158 202). If you do use the stock Mazda radiator (which should be sufficient for a mild V8: stock Mazdas need more cooling than the average engine), then you will need a ‘68 Mustang water pump, which has the lower outlet on the correct side. You will also need to trim the upper water neck on the radiator so that it comes straight out (there is enough neck left to clamp to; I’ve never had a failure), and you will need these radiator hoses: Gates #20923 and #21953. Also, if you use the Mazda radiator, you will need to fabricate a water fill, as the Mazda fills on the engine, and the Ford fills on the radiator (see photo). This would not be a problem if you use a custom radiator. An electric fan will have to be used (I use a 16“ model mounted in front of the Mazda radiator (but mounted behind for the Griffin, which mounts farther forward)). Also a good idea is to use a trans cooler. I use an RV one by Tekonsha (available at Camping World, but similar ones can be had at most parts shops).
The oil pan used is the FOX body (’79-up Mustang, Fairmont, Cougar, Capri, etc.) , with only slight dimpling of the forward sump to clear the steering rack. Something I found is that with this pan comes the need to use these year engine blocks, as the dipstick is on the driver’s side rear, and there is a boss cast into the block for it. The earlier blocks had no such boss as the dipstick goes in the timing cover in front. This is the situation with mine, and now the dipstick doesn’t show true oil level as it only goes into the small front sump (and had to be cut down).
The swaybar has to be replaced, as the stock one goes above
the steering rack, and right about the location of the Ford oil pump. I had Quickor Engineering (a large aftermarket suspension
supplier in Oregon) make a new one to my specs. They will supply you with the same unit
(they should have all the dimensions still). Follow the link to their website. Ask for the
Mazda RX-7/Ford V8 1 1/8“ bar. The springs I used are by Tokiko, but Eibach or
Suspension Techniques will work fine. The fronts are progressive rate and were left as
they came out of the box. The rears are straight rate, and I cut 2.5 coils out to get rid
of the rake (by the way, the spring and strut modifications were done while the car was
still Mazda powered; it just happened that the settings worked even better after the V8
was installed!). The struts are Tokiko HP non-adjustable. I beat many cars with adjustable
struts while out at the track autocrossing. My feeling is that unless you have done all
you can to improve your driving skills, and can’t get that last hundredth of a second
out of the car, you really don’t need the added cost or complexity of the adjustable
type.
Some of the other little things involved. The brake booster vacuum line
needs to be cut as shown (below) and the hose run to the port on the manifold. The stock
fuel pump can be used, just install a tee down where the hard pressure & return lines
end, and run one line up to the carb. The return line will need to be pinched a bit to
build the 5-7 lbs. pressure at the carb (otherwise it would rather just go back the return
line). If you use fuel injection, just connect the stock lines to the injection unit.
Remember to use a new in-line filter!
The heater lines hook up at the firewall like
stock. If you use the AOD/Carb setup, you will need to fabricate a new linkage end at the
carb, and lengthen the AOD arm so that the throw is the same. Also you will have to
fabricate a throttle linkage that the Mazda cable can operate. I made mine from an older
Nissan carburator, but there are many that you can start from. You need to make sure the
throw is the same, and the pivot point is right. In this I’m sorry, but it was five
years ago, and all I remember is spending days fiddling until I got it right. There is no
substitute for careful measuring and craftsmanship here, and every carb/injection setup
will be different. The throttle cable bracket was made from one of the old Mazda underhood
component brackets (coil, I think). Again each combo will be different.