Would a gear swap warrant a tune?

fatboyq

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on a 98 LSC, can I put put in 3.73 gears and call it a day? my friend did this on his 02 GT and did not get a tune his is auto and runs great, speedo is off that is the only thing.

Will the mark run and shift fine without a tune? dont care if the speedo is off by a few.
 
The speedo will be dead on because it reads off the ABS sensors...

On a 98 LSC going from 3.27's to 3.73's will be fine because it is withing the adaptive learning's 2 jump ability....

That being said GET A TUNE.... a tune should be the very first thing any Mark VIII owner gets if they want performance!!
 
You should be fine with 3.73's but you might hit the rev limiter once in awhile in drive. You basically need a tune to firm up your shifts and raise the rev limiter and to take out the timing retard between shifts.
 
I went from 307's to 373's and didn't tune the car for a long time.

The only real issue is the shift schedule gets "compressed".
The car will upshift sooner than it did previously.

Now.. since your going from 327's to 373's As KK mentioned that is within the adaptive strategy's adjustment range.

It would be better to get it tuned, but in your case it's not a "HAVE TO GET IT TUNED" issue.


IMHO: going from 327's to 373's your probably going to be disapointed.
I "was" when I went from 307's to 373's.. the "amount of gear change" was so small that IMHO it wasn't worth the expense.

Try this.
Get out on the highway, at your normall cruise speed.
then Turn your OD off.
The RPM's that you are cruising in 3rd are very close to what you would be running in 4th gear with 430 gears.

With a 307 car, the above scenario is similar to running 410 gears.

I wish I had done this before I got the 373's.. as I would have went with 410's or 430's.


Here comes the trademark tommy offer:

Set up yours with 410's.. if after you install the rear end.. if 410's are too much gear for you, I'll TRADE you my 373's for your 410's.

You would be the 10th person I have made that offer too.. and to date.. not a single person regretted the 410 install.

With that said.. the "offer stands".
 
I almost thought that the 4.10's were a little weak. I wish i would have done the 4.30's. But when i did the tune afterwards, i was very happy, but still, i'd go with the 4.30's unless you do a lot of highway driving. I drove from Chicago to Houston with my 4.10's and had no issue at all.
 
I almost thought that the 4.10's were a little weak. I wish i would have done the 4.30's..


That is because you went from 327's to 410's..
like I mentioned above is a very very minimal ratio change... like going from 307's to 373's

327 to 410's is about a .7 ratio change
307's to 373's is also about a .7 ratio change.

When you change ratio by a "full point" you get the "feel" you were looking for. In order to get the "bang" you were looking for you are correct, you'd have to go to a 430 gear in an LSC.

Gears, GO BIG or not at all.. IMHO
 
I went from 307's to 373's and didn't tune the car for a long time.

The only real issue is the shift schedule gets "compressed".
The car will upshift sooner than it did previously.

Now.. since your going from 327's to 373's As KK mentioned that is within the adaptive strategy's adjustment range.

It would be better to get it tuned, but in your case it's not a "HAVE TO GET IT TUNED" issue.


IMHO: going from 327's to 373's your probably going to be disapointed.
I "was" when I went from 307's to 373's.. the "amount of gear change" was so small that IMHO it wasn't worth the expense.

Try this.
Get out on the highway, at your normall cruise speed.
then Turn your OD off.
The RPM's that you are cruising in 3rd are very close to what you would be running in 4th gear with 430 gears.

With a 307 car, the above scenario is similar to running 410 gears.

I wish I had done this before I got the 373's.. as I would have went with 410's or 430's.


Here comes the trademark tommy offer:

Set up yours with 410's.. if after you install the rear end.. if 410's are too much gear for you, I'll TRADE you my 373's for your 410's.

You would be the 10th person I have made that offer too.. and to date.. not a single person regretted the 410 install.

With that said.. the "offer stands".

I'm agreeing with you... AGAIN!:eek:

If I was doing it again I would have done 4.30s. I would recommend the tune no matter what gears you go with even though with 3.73s it not a requirment.

And keep in mind there is a very good chance you will need a drive shaft once you swap gears. The stock shaft is prone to vibration and the higher shaft speed with gears can make it much worse.
 
I'm agreeing with you... AGAIN!:eek:

If I was doing it again I would have done 4.30s. I would recommend the tune no matter what gears you go with even though with 3.73s it not a requirment.

And keep in mind there is a very good chance you will need a drive shaft once you swap gears. The stock shaft is prone to vibration and the higher shaft speed with gears can make it much worse.

dammit rich.. your taking all my FUN out of the inTARweb.
STOP agree'ing with me dammit!
(joking smile)


I agree with what you said about the tune, in the case of my car.
AFTER I tuned it for the 373's it instantly picked up the .3 of a second I was "missing".
Similarly modded cars were running .3 quicker than mine.. I work and work and worked to find those "missing numbers"...low and behold.. after the tune WALA... three tenths quicker.
I got .3-.4 out of the gears, and .3 or so from the tune.
Overall I was pleased with the outcome, but disapointed in how little the gear change was.

410s-430's are a minumum IMHO.

of course there will be those that say.. PUT 3.55's in it?
(shakes head)

THAT would be a total waste of gear lube and effort IMHO.
the difference between 327's and 355's would be almost immeasurable looking at the stock tach.

Hell changing from 225-60-16's to 245-50-16's would be about the SAME gear change as 327's to 355's.
LMAO
 
.

Hell changing from 225-60-16's to 245-50-16's would be about the SAME gear change as 327's to 355's.
LMAO


Actually now that you mention it, Take into account that if you are going to be putting bigger wheels on like 18" Saleens from bagged taco, that you are definately going to want 4.30 or greater.
 
I know I should do the 4.10s but I really like high speed cruising(85-90)+ average on long trips and don't want to strain the engine. I know the 4.6 likes the high revs with no probs, just need more convincing I guess. I have a problem keeping tires for long as I love sliding through the corners and kicking the rear out any chance I get:rolleyes: . I drive safely, just very aggressive:D . I figured with 4.10s I would have a real problem keeping my foot off the gas. :confused: :confused: :confused: I'm ok with the 3.07s so I figured when I do the trac loc I'd just throw in some 3.55s. I know this choice will probably bother most of you, sorry. Might still go 4.10s. Convince me please.:(
 
Well, from experience, the 4.10's wont disappoint. You will feel a real difference if you decide to go with the 3.55's you will definately notice no change. Gears are one of the many things that leaves you wanting more.

I know I should do the 4.10s but I really like high speed cruising(85-90)+ average on long trips and don't want to strain the engine. I know the 4.6 likes the high revs with no probs, just need more convincing I guess. I have a problem keeping tires for long as I love sliding through the corners and kicking the rear out any chance I get:rolleyes: . I drive safely, just very aggressive:D . I figured with 4.10s I would have a real problem keeping my foot off the gas. :confused: :confused: :confused: I'm ok with the 3.07s so I figured when I do the trac loc I'd just throw in some 3.55s. I know this choice will probably bother most of you, sorry. Might still go 4.10s. Convince me please.:(
 
know I should do the 4.10s but I really like high speed cruising(85-90)+ average on long trips and don't want to strain the engine.(

When I did the trans swap on my first gen, it made the mistake of following the incorrect pin out printed in the tccoa article.

That in turn left me with ONLY 2nd gear, and I was 225 miles from home.

I drove my car IN second gear for over 4 hours at 55MPH.

That MPH in second gear put the car between 4500-5000ish RPMS.

The car suffered no ill effects from it and ran for another 50K miles before it was stolen.. at the time it had right AT 350,000 miles on it.

SO if a worn out tired almost half a million mile motor didn't expire from running high rpms for extended hours on end, I honestly dont think your motor will "mind" lumbering along at 2900-3200 RPMs
 
I have zero qualms about cruising at 3200 rpms.... Hell I don't doubt I will make the 20 hour trip to Houston again with 4.30's....
 
I know I should do the 4.10s but I really like high speed cruising(85-90)+ average on long trips and don't want to strain the engine. I know the 4.6 likes the high revs with no probs, just need more convincing I guess. I have a problem keeping tires for long as I love sliding through the corners and kicking the rear out any chance I get:rolleyes: . I drive safely, just very aggressive:D . I figured with 4.10s I would have a real problem keeping my foot off the gas. :confused: :confused: :confused: I'm ok with the 3.07s so I figured when I do the trac loc I'd just throw in some 3.55s. I know this choice will probably bother most of you, sorry. Might still go 4.10s. Convince me please.:(

I think you will be very disappointed from 3.55s. Personally I wouldn't do anything less then 4.10s. 80-85 is around 3000rpm and I still get over 20mpg at those speeds. And remember until the 80s overdrive transmissions were vertually non existant. Plenty of people had 3.55s, 3.73s or even 4.10s in there cars.
 
Last year I went with a 3.73 gear in my 99 mustang GT and was not happy $500 later I could barely tell a difference, the Mark will see 75% highway travel and 25% city so that is why I did not want a big ass gear, it will also see winter duty, Rain here in chicago. With 4.10s and rain, snow it will make for a hairy ride...

just thinking of what to do, dont even have the car yet LOL!
I have a friend who charges $220 for a gear swap with fluids etc... I can pick up a gear for $100 from a local shop. So it will be aout $350,

will a SCT x cal from a 96-04 GT/cobra work on these cars?
 
If you said 4.10s in rain and snow would make for a hairy ride wouldn't that be a reason not to go to the 4.10s? I drive mine all year so this was also a consideration of mine too.
 
If you aren't an idiot 4.10's should be no problem in bad weather... I drive my Vic with a tlock and 3.55's all winter.... just don't go mashing the pedal in bad weather....
 
I have 4.10s, trac lok and a 3500 stall and the car does better in the snow then it did with the open dif and 3.07s. The only problem I have is the 1-2 shift is set up very firm and will put the car sideways with little effort when the roads are slick.
 
I love snow 'drifting'. The worse the weather the better the driving. I just wish all those people that can't drive would stay home. I love it when guys in Jeeps who can't drive try to keep up in bad snow.:D Hey KK how do you like the 3.55s? Was that stock in those cars? Curious why you don't have 4.10s in there too.
 
90% of the time it will not see snow... I usually buy a beater every year around oct and drive it till march and sell it, usually spend 2-3k for one and at that price they dont drop much.
 

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