Steve Sindt

Just got a 1990 mustang gt, has some mods. Edelbrock performer intake, full bbk exhaust, just installed 3 core radiator. Was going to replace my spark plugs with autolite 25's, but just pulled one out and it's an autolite 2545 it's longer. Read a bunch of forums. I don't see gt40/p or 3-4 bars on the heads. The only thing I see is an S on the head casting back drivers side near master cylinder. The pervious owner don't know much about it. It's in pretty roughy shape, but its a 25th anniversary convertible the interior is in mint condition a plus. It's a project for me and my 8 year to clean up and enjoy.
New to these mustangs..

Also it's running hot has an electric fan installed and comes on at 185, stock gauge wants to peg out. I know there not the best, but hooked up my dmm with temp wire attracted to thermostat housing. Mechanical meter on order. It's reading max 210 with our foot into it. Seems to cool down when stopped. Temp goes up on hwy and in town. Side note thanks to all the help replaced the 160 t-stat for 180 burped the system. Still getting to 210. Thanks for help.

Steve Sindt

Also forgot to say autolite 25's don't fit, seem to short.

Steve Sindt

Also just saw a 17 I believe stamped in the front casting by a/c compressor. Starting to think this motor is and 85-86 no HO lower end with the edelbrock intake and 19# injectors. Any one wanna help?

lxman1

According the the Autolite website, the 2545 fits 86 Mustang 5.0HO only. I would say you have an 86 roller motor.

http://www.autolitecatalog.com/PartD...px?b=A&pn=2545

As for running hot diving but not idling, is usually a flow problem. Usually a clogged radiator, but since it is new, I would say it is ok. I would inspect the lower radiator hose. They often have a spring in them to keep them from collapsing at higher rpms. At normal operating temp, run it up to about 2500-3000rpm and watch the bottom hose. See if it sucks together. If so, replace the hose. If not, it could be a worn impeller on the waterpump or perhaps a bad head gasket. The electric fan seems to be pulling enough air if it stays cool idling.

Steve Sindt

Thank you for the information!
That stinks if its the 86 motor... Im going to try and get the vin off the block tonight. Hoping maybe they just put the 86 heads on the block.

mjr46

what heads are on the car?

Steve Sindt

I don't know. All I can see in casting is 17 and S, the heads fit a 2545 plug not 25's. haven't check motor vin yet. I think the motor or the heads been swapped at some point in the cars life.

Steve Sindt

Well looks like I got hosed on this car.. The firing order isn't HO, wasn't able to see engine number. Soaking it in degreaser, so I now think its a motor out of an xr7 cougar do to the fact I think it's e6 heads. Man this sucks!! Well I think I'm gonna cut my loses and dump the car see if I can get my $1700 back...
So in your opinions what should I list the mustang for?

1990 mustang gt 25th anniversary convertible
Bright regatta blue/light titanium silver

Good
Runs and drives well
New top
Interior is almost mint (minor stains in carpet no dash damage)
New radiator, hoses, t-stat, and coolant flush
New plugs, wires, MSD cap, and rotor
Full BBK stainless Steel exhaust
Edelbrock performer intake
BBK 65mm throttle body and spacer
Newer tires
New battery
3:73 rear end with royal purple oil

Bad
Has aftermarket ram air hood (not painted and hood pin style)
Has minor rust spots (Wisconsin car)
Clear coat bubbling off
Needs alignment
Convertible frame has the a crack starting
A/C is leaking Freon