Considering a switch from 1999 4.6l 2V to Blueprint 347 / T5

[DenverSteve]

My kit is a 2018 MKIV setup for a 1999 Mustang GT 4.6L SOHC 2V with a Borg Warner T45 transmission.

Since 2018 when I purchased my kit, my budget has grown. I'm now about ready to rebuild my engine and I'm considering changing to a Blueprint 347 fi (https://factoryfiveengines.com/ford-347-c-i-fuel-injected/) with Alternator and PS option (Package Option 2), and to use a bell housing backed with a Borg Warner T5 I have from a 1995 Mustang 5.0 - assuming they bolt up.

Couple questions...

1. How much work will I need to do on my frame to bolt up the new engine/transmission configuration? I'm guessing I'll need to move the engine and transmission mounts? Maybe this is a question for factory five direct?

2. Will the ps pump from Blueprint drive the Power booster brake master cylinder and power steering from my 1999 mustang gt donor car?

I assume I'll need to make a new driveshaft.

Thanks,

Steve

[rthomas98]

Some thoughts:

- T5 transmission choice behind the 347 is a bad idea unless you are going to do some serious upgrades to it. They are only good to a max of 300 hp. You will want to seriously consider going TKX.
- Inline with the above what are you doing to the rest of the driveline? Do you plan any updates to the rear axle? Not sure what gear or set-up you currently have. Yes you'll need a new driveshaft. But you might not need to make it just order one from factory five.
- As far as the powersteering you might want to ask Blueprint that question as I know they spec their pumps based on the powersteering option from Factory Five

[DenverSteve]

Some thoughts:

- T5 transmission choice behind the 347 is a bad idea unless you are going to do some serious upgrades to it. They are only good to a max of 300 hp. You will want to seriously consider going TKX.
- Inline with the above what are you doing to the rest of the driveline? Do you plan any updates to the rear axle? Not sure what gear or set-up you currently have. Yes you'll need a new driveshaft. But you might not need to make it just order one from factory five.
- As far as the powersteering you might want to ask Blueprint that question as I know they spec their pumps based on the powersteering option from Factory Five

Thank you. I see the T5 is rated only for up to 300 lb-ft of torque. I was thinking the lighter the car, the less torque the transmission experiences before the wheels break loose, and was thinking it would be fine. You got me thinking though and I'll definitely do more research and consider something else.

The rear axle is a Ford 8.8 with 3.27:1 gears from a 1998 Mustang GT.

I appreciate your input - thanks!

[David Williamson]

Your back axle will be fine. There are no changes to the frame to switch engines just engine mounts. If you have a power steering rack from FFR or a Fox Mustang the pump set up from Blue print should work fine but check just in case.
David W

[efnfast]

Imho the T5 is my cobra is one of my most favourite transmissions.

It's lived almost 20 years with 600ft-lbs

But it was built up with Astro gears, 9310 mainshaft, etc.

I would do a built T5 transmission any day over a TKX, although my understanding is Astro parts are basically NLA so you'd be using G-Force parts today

[rich grsc]

Some thoughts:

- T5 transmission choice behind the 347 is a bad idea unless you are going to do some serious upgrades to it. They are only good to a max of 300 hp. You will want to seriously consider going TKX.
- Inline with the above what are you doing to the rest of the driveline? Do you plan any updates to the rear axle? Not sure what gear or set-up you currently have. Yes you'll need a new driveshaft. But you might not need to make it just order one from factory five.
- As far as the powersteering you might want to ask Blueprint that question as I know they spec their pumps based on the powersteering option from Factory Five
Thats just bad info and advise. A t-5 from any Mustang will last just fine behind a 347. I know a several in our club, none have had any problems, I have 400 hp running through mine. These cars are about 1200# lighter than a Mustang so no worries.

[Derald Rice]

The weak link in any street driven Cobra has always been and will continue to be ....the rear tires.

Too many people have swallowed the kool aide about T5's being weak.

[Redstang69]

Surprised nobody mentioned this, but I think the T5 out of the Cobra mustang have the more desirable gear ratios for our cars. Do a little searching and I think Jeff K has posted a good bit of info on the regular T5 vs the Cobra spec T5 paired with different rear end ratios.
I'd think you'll also need different headers but FF could tell you.

[StangRacer]

Surprised nobody mentioned this, but I think the T5 out of the Cobra mustang have the more desirable gear ratios for our cars. Do a little searching and I think Jeff K has posted a good bit of info on the regular T5 vs the Cobra spec T5 paired with different rear end ratios.
I'd think you'll also need different headers but FF could tell you.

Also available is the T5 "Z" with the 2.95 first gear...

[skidd]

I can't help you with the frame mods needed.
But ..
T5z (what I have) is supposed to be rated to handle 350lb of torque, and has better gear ratios over the standard T5wc from a mustang. T5z with 3.55 rear gear behind it is a nice combo with my 302. I've never driven a F5 with a T5wc, but I'm told 1st gear is over way too quick.

[Erik W. Treves]

My mark1 had a junk yard T5 in it for years (out of a 4 cylinder in fact....- 460rwhp - 3rd gear blew up at the autox track at like year 10.... switched to world class T5 and to my knowledge that transmission is still in the car. My car was a DSS 331 with supercharger with 3:27 gears and it was plenty of fun.

[TBull]

Like others,
I had a T5 Z world class on my previous build where I was about 445 at the rears so well over 5 at the crank and it survived for about 8 years with 3:55 rear gears until I shattered 2nd gear. Loved that transmission. You could almost slap it into gear. A regular 347 should survive just fine.

[Jeff Kleiner]

I ran a T5 behind a mild (325-340ish HP) 5.0 in my Mk3 and beat on it mercilessly but it never complained and shifted like butter.

Jeff

[john42]

Have you considered the Ford Boss 347 crate engine vs the Blueprint. When I bought mine (from Forte) I got a better deal on the Ford Boss and it also seems a bit better quality.

[DenverSteve]

Have you considered the Ford Boss 347 crate engine vs the Blueprint. When I bought mine (from Forte) I got a better deal on the Ford Boss and it also seems a bit better quality.

I haven't - didn't know that Mike was offering a build. Will definitely reach out to him. Thanks!

[DenverSteve]

The weak link in any street driven Cobra has always been and will continue to be ....the rear tires.

Too many people have swallowed the kool aide about T5's being weak.

I too really believe the torque experienced by the transmission is a formula considering engine torque, rear end gear ratio and rear tire traction. The 3.27 gear will add more torque to the drivetrain, but with a straight axle I can't imagine getting enough traction to push the limits of the T5. I too really like the gear ratios on the 1995 Mustang 5.0 T5, so I think I'm going to give it a try.

Thanks everyone for your comments!!!

[CNIdog]

Don't forget your exhaust setup will need a change. Different headers?

[Ford & Jeep Fan]

The decision as to which trans to use is yours. I Grenaded 2 different T5s (1 trans blew Twice, Total of 3 Implosions) in a 85 Capri 5.0L that only had a exh change. This was back in 86-87. I later bought a New 88 GT Mustang and that one did live longer. I did swap to a lower rear axle gear that i think took some stress off the transmission.

Both these cars did time at the 1/8the mile Drag strip. None of the trans failures happened at the race track.

Trans Longevity lies in the driver's hands. You know how YOU DRIVE, Choose Accordingly.

[CraigS]

If it's in the budget a new T5 of some variety is a great choice. But, you can also use what you have and replace when needed. It will also give you some experience w/ the standard T5 gear ratios. So you have some reference when thinking which new one to buy. Long ago I had a standard T5 behind a stock 302. It had that short first gear that most like to replace w/ the taller version. Yeah, for the absolute best 1/4 mile times it wasn't ideal. But it sure made driving the car in normal traffic easy. You could almost leave a stop w/o hitting the gas. No matter which 1st you have it is pretty much worthless because you just lite up the tires in any of them at full throttle.

[Derald Rice]

Another item to consider is that a 94-95 T5 has an input shaft that is 5/8 of an inch longer than the input shaft from a 87-93....

There are two options to use your 95 T5. one is to swap input shafts another is to use a 94-95 bellhousing.

here is an excellent read about the history of T5's:

https://www.moderndriveline.com/the-many-different-faces-of-the-t5/

[DenverSteve]

Another item to consider is that a 94-95 T5 has an input shaft that is 5/8 of an inch longer than the input shaft from a 87-93....

There are two options to use your 95 T5. one is to swap input shafts another is to use a 94-95 bellhousing.

here is an excellent read about the history of T5's:

https://www.moderndriveline.com/the-many-different-faces-of-the-t5/

Didn't know that. Thanks - I do have the 1995 bell housing that came with the transmission, so hopefully it will be okay.

After reading the article, it looks like the 95 bell housing and T5 will push the shifter 5/8" further back... Will need to investigate that before investing too much on this setup.

[rich grsc]

The whole 95 bell housing/transmission setup is less than ideal. As said it moves the transmission back, possibly complicating the driveshaft fit. Another issue is if you try to fit an aftermarket oil pan with bump outs, the clutch cable will hit. The clutch arm is in a different location and angle, causing the issue

[StangRacer]

Didn't know that. Thanks - I do have the 1995 bell housing that came with the transmission, so hopefully it will be okay.

After reading the article, it looks like the 95 bell housing and T5 will push the shifter 5/8" further back... Will need to investigate that before investing too much on this setup.

Swapping the input shaft on the 1995 T5 to the shorter input to use the Foxbody depth bellhousing is an easy task. I ran a T5 out of a V6 Mustang in my CMC car with a Foxbody length input that was purchased off ebay and never had any issues...

[Ford & Jeep Fan]

Also If i remember corrrectly If in the future you need to swap from a T5 to the TKO/TKX The 83-93 T-5 Bellhousings can be just drilled for 2 or 3 of the trans mount bolts and used with a TKO/TKX trans. (Might need a clutch disc swap)