FINALLY, SOMETHING I KNOW!!! i've owed both an sr5 and gts(still have the gts)
sr5 is carbed.. sohc 70hp 4ac engine.. it has rear brakes but they are drum brake(gts is disk). rear end is different, drive shaft, transmission(t50 just like the gts but different final drive ratio), speedo redlines earlier and only goes to 110(gts gots to 150), seat are different, steering wheel is like a boat wheel in the sr5, theres ALOT of little differences...
sr5's are cheaper but i would only buy one if it's going to be a swap project or daily driver. they run for about $1000 give or take a few hundred. i would deffinatly buy one if i was planning on swapping..
THERES A KA242DE(98) powered gts hatchback, full race(cage/ stripped) for sale on
http://www.club4ag.com right now he said he would sell for around 3.5-4K.. easy to make into street legal..
if your planning on keeping a twin cam 16valve 4age engine then a gts would be better.. its just all the little things that are better but why not?
theres also a F20C(s2000) powered ae86 and theres even a few sr, rb swaps going on...
now the technical part.. straight from club 4ag tech reference...
4A-GE engine (and all brackets to support peripheral equipment)
Most peripherals such as A/C, P/S pumps and compressors
Complete intake and exhaust runners and headers
Fuel pump and lines
Gasoline tank, evaporation and related items
Clutch fork and fluid line locations and bell housing (GTS and SR5 has opposite side clutch fork and slave due to the differences in the exhaust runner location and is extremely important not to run fluid lines next to exhaust systems)
Transmission is the same unit as the GTS (T50C), however the speedometer gear is different, and must be replaced to read correct speed on the cluster. (due to different final drive ratio)
EFI computer triggers and sensors
AFM or MAP
Air Temp Sensor (MAP only)
distributor assembly (MAP and AFM based are different)
Igniter and Coils (different for AFM and MAP based)
EFI Computer (MAP or AFM specific)
House Harness and Engine Harness and related junction boxes
All relays and VSV triggers
peripheral VSV triggers
Battery terminals and fusible link terminals and fuse box
some of these can be ignored for carburetor use such as Weber Side-draft carburetors
Ignition system
Dash Cluster missing check engine (W) lamp
Labor and Installation Professional who can proceed properly so as not to create more problems (cheap or un-skilled installer would render the 4A-GE less powerful and unbelievably unreliable.
Oil cooler, block and lines
Clutch and flywheel Now as for other items that are mechanically different from the GT-S (4A-GE equipped models):
Differential carrier
Differential gear, axles, hub assembly (need 4A-GE unit to utilize commonly available LSD)
Rear disk brakes vs. drum and related lines and cables (except Japanese GT)
Steering rack, knuckles, tie rods
Propeller shaft
Clutch fork, assembly, cables, lines, bell housing (as mentioned above)
Front and rear suspension are different from factory in spec but can be interchanged (Not significant as most owners replace them with aftermarket systems anyway)
Body and trim differences:
Seats, panels and trim
Outside mirrors (some were equipped with power as on the GTS, while others were fixed manual units)
Tags and Emblems (obviously...)
Front bumper lower spoiler
Fender protector on 86-87 models
Trunk moldings on 86-87 2 door coupes
Rear spoiler missing on 84-85 SR5 3 door hatchbacks
Color variations inside and outside
Body side moldings
Number of spot welding in key frame members on 86-87 models
ETS Cassette Radio player (Ok, not important at all)
Rear Wipers, Power Windows, Sunroof only optional on GTS
Auto Climate Control (Japan Only)
heres the link if you want more info on differences and 4ac to 4ag swaphttp://
www.club4ag.com/faq%20a....html