PDA

View Full Version : A few Mustang Questions



backformore
12-24-2005, 07:00 PM
A friend has an 85 LX 5.0 with T-tops and I have a few questions that I hope some of the Mustang experts can answer easily.

1. Will the 5.0 drive train drop right into an 85 tub(w/o T-tops) without any modification?

2. Can the 85 engine be converted to 86+ FI by bolting on the appropriate manifold etc. or is it much more involved?

It would be used for track days and autocross, not AS or anything like that.

Thanks

Rory

Ron Earp
12-25-2005, 10:28 AM
Originally posted by backformore@Dec 24 2005, 07:00 PM
A friend has an 85 LX 5.0 with T-tops and I have a few questions that I hope some of the Mustang experts can answer easily.

1. Will the 5.0 drive train drop right into an 85 tub(w/o T-tops) without any modification?

2. Can the 85 engine be converted to 86+ FI by bolting on the appropriate manifold etc. or is it much more involved?

It would be used for track days and autocross, not AS or anything like that.

Thanks

Rory

69160


I used to have an 85 LX Notchback car. Quite fast. It will drop into a chassis with no trouble, but, the 85 has a single hump transmission mount that allows only one exhaust pipe to pass through. Most folks replace this to a two hump piece so you cna run true duals.

If I were you I'd use the carbed 5.0L motor from 85 and work on it. It is a great performance base and you can ultimately get just as much power out of it as the FI 5.0L motor. The 85 5.0L in the GT/LX is a roller cam motor so you've got that much working for you. Go for a bigger cam, bolt on some aftermarket heads, headers, intake, and carb and you'll be in good shape for a track day. Shop used and save a ton. I made mine quite fast back in the day with no trouble at all.

Converting to EFI is involved - in tank pump, intake, MAF system, computer, fuel return to tank (non-EFI will not have this) etc. Parts are out there, but you'll come out easier and cheaper to go the carb route since you've got a great starting point for a 4bbl hell raiser.

The 85 chassis does use the 7.5" rear end though, not as good as the 8.8" rear, but they can work just fine. You are probably going to want to get an 8.8" rear and the disc brake conversion kit for it anyhow. Or, find a rear end from a SVO Mustang (rare) or get one from a Thunderbird TurboCoupe (not so rare) since these have disc brakes and will bolt up to your 85 fox chassis. Plus, these rear ends already have good gears (3.55, 3.73) you'll probably want to your track car.

The standard T5 in the cars will last awhile, then when it blows up (it will) you can upgrade to a Tremec or get the improvement kit for the T5. Or, alternatively, buy used T5s all day long for $100 and put a new one in each season. I've heard even the later model T5s with the upgrade kit still isn't all that great, but I'm sure the AS crowd would know a lot more about this.

Ron

PS-if you must go EFI remember the 86 and up are not all the same. You want a MAF EEC-IV system that started at different times in CA than the rest of the country. Get a 89 and up and you'll have the same stuff that will be sure to work with aftermarket programmers like the Predator, etc.

trueblue
01-10-2006, 01:27 AM
Ron I would have to say you just about covered it all. :023: