rwd swap

[anonymous48420]

Hey guys its been a while and a few cars to say the least since I've been on here but I've had a few epiphanies and their slowly driving me mad. So here it is im looking to finally buy a car again after 2 hurricane seasons soon to be 3 and 21,000 miles on a 2 stroke scooter.
A few years ago had purchased a BMW 540i and loved it to death. Very few cars in the us can out handle out stop and out accelerate a corvette of the same year stock vs stock and this was one. 300 hp and 324 lbs of torque and 1g in the corners is a boat load of fun. Well times got tough after moving 1500 miles from every one I know so I sold it to pay bills since I hadn't found a job at that time and im still kicking myself in the rear.
Well anyways I miss the feeling that car gave me just looking at it much less driving it. I've been finding them pop up on Craigslist lately for dirt cheap with a blown motor or trans and that's when I decided to hell with my v8 binge. Gas wasn't cheap and the weight and size was a pain in the neck sometimes. The 528 uses better suspension and weighs less along with way more suspension parts. They also have a much higher failure rate on the engines and trannys.
Basically any day I can get one for 800 or less in good condition. I need to figure out which 3x00 would be best for a rwd swap and make it happen. I know for a fact one will fit easily no questions asked. A ford 5.0 v8 slides into the smaller frame and more than a few companies make kits to do so. They also make kits to mount the sbc into the larger frame rail 540 but I'm set on a v6. I've been itching to build a 60*v6 for over 10 years and now is the time.
Personally I want a 3.9l but i think the fancy 3.5 would work for me with the 3.9" bore. I'm looking to punch out the holes to 4.0" and use the ls1 pistons and sbc con rods to match. I remember from before that was possible and would make a good improvement in torque in theory along with leaps ahead reliability wise. Maybe a lopey cam that packs a punch and some other goodies for the top end. I don't really want a vvt motor though as I have zero plans to use it. I'm thinking of an obd1 7730 Pcm for ease of use. The BMW body I might add has all of the gauges tied to the body except for the tach. And I mean everything. All id need to do is put an order in with tce and get a crank trigger kit to match the BMW,s crank sensor tooth count and I may be able to get all the stuff to pls nice if I'm lucky. If not I can most likely have a safe to drive ride with no wiring really needed aside from the 7730 to the engine and trans.
I'll be trying to go with a stick because I love manuals and even though my knees aren't the best ill grit my teeth and just call it a cheezy grin when I drive it. I know of a bolt in crossmember for the t5 trans that I believe the transmarobirds used so if I can figure out a clutch and flywheel to use with the 3.5 or 3.9 I can just bolt them together and make some mounts for the engine and have it set in. I know some driveshaft people I did business with in the past for my old beamer that make custom shafts all the time for beamers with swaps so all I,need to tell them is the overall length between the trans and rear end and they can whip me up a shaft with the right splines on the front for the t5 and have all new HD u joints and center support bearing.
So my main questions are which is more rwd swap friendly the 3.5 or 3.9 and what clutch am I going to need to track down along with a flywheel that will work with what starter?

[caffeine]

For a T5 you're best off using a 88-94 J-body V6 flywheel, and depending on what the T5 is coming from a clutch kit for either a 85-92 F-body V6 or a 93-95 F-body 3.4.

The stock VVT timing cover HAS to be used on the VVT engines unless BCC is still making RWD covers. The stock cover is possible to use but it limits where accessories can be placed because of the water pump location and the coolant crossover. A custom crossover could be fabbed for the rear of the heads instead to free up a little bit of room up front.

Realistically the 04-06 3.5 makes for a significantly easier RWD swap.

Also there's no point in doing an 07+ 3.5 over a 3.9. They're pretty much exactly the same on the outside.

[Guest]

Depending on what application the T5 comes from that may cause a problem with flywheel thickness. So stay away from 3.4 (4th gen F-body) T5, since this uses a thicker flywheel, and will not be easily compatible with the FWD block. That being sai I am using a 3.4 flywheel behind my FWD 660 (an LX9), and have a 14mm spacer between the block and the starter to account for the larger diameter of the RWD flywheel.

It will be easiest to a T5 from just about any other 660 application and use the thinner FWD flywheel, J-body, H-body, L-Body, etc all used the same thickness flywheel.

After all of that I will suggest that you look for something other than a T5. I didn't put a T5 behind my LX9, because I know it simply wouldn't have lasted, and I had one in my garage that I could have used. It might have been ok at first, but I plan on making plenty more power than a T5 is rated for. I have also gone through 2 T5s one at stock HP levels and one at higher than stock levels in an S15 Jimmy. There might also be an issue with the FWD starter location and the clutch fork location of the T5. In my case I used a Nissan FS5R30A from a 1992 300ZX, because it's known to take 700+ HP in stock for in a car that weighs nearly twice as much as my car does.

If a friend of mine goes through with it we will be installing an LX9 in his Triumph and will likely use an R154 transmission as outlined by this thread: http://www.thirdgen.org/forums/v6/66...on-option.html

[caffeine]

Just so the OP is aware, the F-body T5 input shaft is long enough to work fine with the thin FWD flywheel. At most you might have to extend the clutch fork pivot a bit and use an S10 front bearing retainer (although I've heard the front bearing retainer is optional; it just give more surface for the TOB to ride on). There is no interference between the starter and clutch fork on either S10 or F-body bellhousings. The 3rd gen F-body 2.8 bellhousing is best to get as it has dual starter pockets and you can mount the trans either on an angle like stock or straight up. The 3.1 bellhousing may be the same but I'm not sure.

[caffeine]

As for an r154, look into the AR5 as well. It's basically an updated r154 but can be had with the standard GM input shaft which makes clutch selection a breeze. Also, beyond the Dakota 2.5 bellhousing, also look for an IIRC 99-02 Trooper bellhousing. It should work with both the r154 and AR5 but has the starter pocket on the drivers side unlike the Dakota bellhousing.

[anonymous48420]

Well thank you guys very much for the informative posts. I'm going to have to do some reading and go through that other forum. The main reason for the t5 selection is just because of the bolt in cross members that I could get to take half the guess work of mounting the drivetrain. I contemplated a 700r4 or something of the 4lx0-e from the v6 red automatic cars but I don't really want to have another automatic I love grabbing gears when I drive. Then again the days I may not feel like grabbing them it would be nice to just get in it and go.
How did you break so many t-5's? I thought those were pretty reliable transmissions? Deff not the best but I've rarely seen one break.

[Guest]

Well, "breaking" maybe a bit misleading, The transmissions still worked, but they howled in gear, and got difficult to shift near the end of their useful life, which to me, means broken. They are made from hardened butter, which is better than just straight butter, but still not strong enough for my needs. I've seen a bunch that have literally spilled their guts all over the ground too, granted this usually happens in a high torque, very traction enabled drag launch, but still, there are other transmissions that are known to be stronger.

Also the starter pocket on the 2.8L dual pocket bellhousing is in the wrong spot, at least for using the FWD diameter flywheel, it might work with the 14mm spacer and RWD flywheel, but I sold the one I had because it was going to take modification to make work correctly.

[caffeine]

I used dual starter pocket bellhousing with a 3500 and FWD flywheel and I had to grind a negligible amount of material off the bellhousing the clear the starter correctly.

It may or may not clear fine with a RWD flywheel and a 9/16" spacer, but I have not tested that.

[caffeine]

If you look closely you can sorta see where the grinding was done to clear the starter (uppermost point). But again very minor so not really noticeable unless you're looking.

[anonymous48420]

I can deal with a little grinding that's fairly common for me to have to do at work and it really doesn't affect things over time unless it was a crazy weak spot or flimsy. Also the tranny guy we deal with at the shop can fix the few defects the t5 has for a reasonable price. I'm leary on the other trans as my first choice due to making sure I get the right trans and shafts or get the right ones put in. I've had some really bad luck lately with things of that nature and would hate to end up contributing to that streak. I almost got my hands on a 04-06 3500 from a Saturn vue but it ended up being a 4 banger and I don't really need a wine rack. I may have a few good leads on some t5's but who knows if they will be the one I want. Granted you can swap bellhousings on some but if I remember right there are a few you can't and id end up with one of those if I ordered it.