Will that fit, space is very limited on these f-body's and I thought the physical sizes was quite a bit larger ? I think its larger than the F1a

 

Not larger than an F1a. The volute on the P1R is 3/4" larger diameter than the P1X for reference.

 

Definitely extreme. I think I'll stick with the d1 because I'm really hoping for like 650-700 which I think I can achieve and would rather spend the money on a rear, cam, build the motor, etc.

 

I'd target around 700whp if I may add my $.02.
The T56 design architecture for torque capacity tops out around 750 lb.ft. so past that even with all the viper shafts and what not, the design simply isn't made to handle torque higher than that.
At 700whp you can still retain the stock fuel system and just add twin pumps although a boost referenced FPR would still be recommended, a Stage 2 type T56 will live a long time, clutches are still affordable etc.
Once you start getting over 700whp the cost for support parts goes up exponentially plus a 700whp stick car on the street is still pretty rowdy with a standard summer tire, you'll really need to plan your pulls because you run out of real-estate very fast.
If you can run flex fuel and E85, then that's absolutely what I'd do, you can run E85 when enjoying the car and make easy power then run a few tanks of pump gas through it to clean out the system before parking it for the winter, best of both worlds.
I only have pump 91 where I live so I'm going the methanol injection route and will see where that takes me, but I'd do E85 if my situation was different.

 

Got my payout. This is going down real soon
I plan on e85 plus meth but I figure if I'm doing that on a cammed 6.0 and at least 10lbs boost I'm going to clear the 700 mark so at that point like said above will I kill the t56. I don't really want to buy a new tranny because of the huge cost on that end, I really want to capitalize on what I have currently. I remember seeing the s60 rear as recommended but wanted to see if anyone else had any input because that's by far the most expensive piece I'll be buying. I am also looking at being around 4.1x gearing in the rear. The current car has been wrecked and I found a roller that may be the move to throw this all in. Brakes are high on my list as even with the power I'm putting down now the brakes are horrendous and like to lock up. Any other suggestions before I start ordering?

 

There are two or three fully built T56 on the parts forum right now that are easily half what a new unit would cost so I'd scoop one up.
Any of the aftermarket offerings for a rear diff will be fine, the 9" enables fast gear changes with another 3rd member, fairly quiet, S60 much more involved gear changes, very quiet, 12 bolt much more involved gear changes and can be quite noisy from my own experience.
For gearing I'd be targeting 3.50 or 3.70 with a six speed, those ratios offer the best street manners and still get you a 140-150mph top speed in 4th gear.
There're two 12 bolts with 3.73 gears on the parts forum right now too.

 

I have a built T-56 for sale myself, I'm planning to go over 1000 RWHP eventually so I gotta upgrade. Stage 4 build, really great trans. Shifts like butter, even at 7800 RPM.

My .02 on the rear axle: Everyone says 9" Ford. I disagree. I have an S60 because I never planned on swapping gears ( although I'm going to be, soon ) and easy gear swaps are really the only benefit to a 9", IMO. To build a 9" to have the same power capacity as an S60, it will cost more. The S60 is made for the F-body, including an integral mount for the torque arm, like a factory 10 bolt. Mine gets abused and takes everything I throw at it.

Also, I concur with what TheBallSS says in terms of gearing. I have 4.30's right now and they are almost useless in first gear. I'm swapping to 3.54's soon. You may think you'd like 4.10s until you have a lot of power, and they just become too much.

 

With looking up built t56s and the magnums I'm almost scared to ask what you want for yours.

I'm leaning the s60 but I'm still going to do some more reading and test apart the 6.0 before I make my final decisions but i do want to get going on this sooner than later.

Oh i absolutely listen to ball, he's been commenting on a few of my things and I see his posts on old threads I read and he seems very knowledgeable. There are many experienced people here that make people like me life's much easier. This is my 3rd 4th gen but first manual so I guess a lot of my prior knowledge is etched in for that aspect. 4.10s would probably be the wrong choice here compared to a good one for auto. I have to retrain myself but will look into the 3.5s.

 

I'm asking $2750 for my trans, but I'm negotiable to a point. It only has a little over 1K miles on it, and it's always had synthetic fluid in it. A used high mileage T-56 still brings around $2K, so for the extra $750 you'd get a WAY stronger trans. Here's the ad if you want to check it out: https://ls1tech.com/forums/market/1978825

 

Well car died last night and I'm fighting with that currently but in the sake of staying positive I just found out I already have the 8 rib system on the car so that's a big plus, makes me think I have a boost leak because I'm making only 5 pounds but I'm going fmic soon anyway so whatever

 

Could be belt slip, how old is the belt? Any idea?

 

I don't know and the belt does look like it's not sitting right so its gonna be changed anyway.
before I ask on a new thread, any pointers on getting the belt off? My alternator went out and so far i have three mounting bolts out of the bracket and both threads i found said loosen the bolt at the top of the bracket, which i did. The belt is still tight as hell. One screw is blocked by the sway bar and the other is behind the belt so I'm a little stuck at the moment.

 

Never had a supercharger, so no clue on that one.

 

That's a banging deal for sure.
I paid $2,000 for a Stage 2 T56 4-5 years ago that had been passed around like a joint between three or four people in my friend's group and they all abused it lol.

 

Don't quote me on this but you probably have to remove the blower to get to the alternator and the belt.
Regarding the alternator, don't just buy a stock reman unit, it will also fail, I went through 5 or 6 before I figured that out.
A truck case alternator will fit, you may have to bend some of the P/S lines a bit but it will work.
Find the 160amp Escalade unit, you won't have any issues after that.
I ponied up for a JS Alternators 320-amp unit only because I have lots of electrical loads and wanted full output from idle to 8,000rpm.

 

Noted on the alternator, i thought i remembered somwthing about people swapping in truck ones but hadnt had time to look into it yet.
for the belt I read on another post to loosen the top bolt on the bracket and that would relieve tension but nope still tight as hell. I'm going to read some more on it but the procharger definitely needs to come out to get to the alternator.

 

I just pm'ed you

 

Take the belt off the procharger, then take the head unit out, then the bracket, then the alternator. If the belt is shot, and its still tight on the pulleys after you backed the tensioner all the way off, I would just cut it and order a new one.

Like many have said, I would sell your t56 as it sits and buy the built one. You should be able to get an easy $2k for the stock one and if you get the above t56, its really only a $750 dollar investment. Buy the twin disc, quick time bellhousing and a good driveshaft. I would beef up everything else (rear end, driveshaft, clutch, fuel system) and keep running the ls1 as it is while you build that 6.0 (I'd just do a rod/piston set up) then swap the new engine in with the ls1 top end, At that point I'd change pulleys on the head unit and get it tuned. That would easily hit your 700whp mark.

Best of luck

 

Oh its been hell. The truck alternator I couldn't get to work even with machining down the front like someone else did. It kept fighting the alternator, bolt was backing out a couple times so finally I hit it with a air impact in a bad mood and snapped the bolt off in the procharger, just got it back from the machine shop today, swapped back to the regular alternator and pulley. i have taken out the procharger so many times I'm impressed with how quick I can do it now. Anyways back to the point, turns out I'm already running the 3.4 and 7.65 so pulleys are exactly what I wanted. I ordered rods and pistons, the brute speed blower cam, aem meth kit, the entire motor is going to be rebuilt from the main bearings up, SE duals to pair with the 1 7/8 headers, koni srt lowering kit, 3inch fmic, 0411 ecu to make it flex fuel since I do have e85 local, all new SE rear suspension, and idk I'm probably missing more. Honestly though with having had all these issues with the alternator because I was to determined to make the truck one fit I've decided I need a more practical daily. I found a 06 trailblazer I'm going to buy since daily driving the firebird is a bad idea in a state with snow. Plus I had a 06 before that I absolutely loved so I'm very excited to get another one. It's the 5.3 lh6 so aluminum block, 4.8 pistons, 243 heads, nnbs intake, they did a DOD delete and added a zo6 cam. Should be a fun daily. I'll either hold onto the ls1 to put in that or sell it to recoupe funds to throw into the firebird. The 6.0 I already tore down so probably going to clean it up and start rebuilding it tomorrow as all I am waiting for is rocker arms, cam, and measuring out the pushrods.

 

Also, haven't forgotten about you - Just working on getting a more realistic quote for shipping. They were asking for almost $700, but that was quoted on a pallet, which takes up more space.