Manual trans other than t-56 or old 4 spd
 

I'm collecting parts to swap an LS series engine into an MGB, but my budject cant quite take a $2000 transmission, plus the T-56 is fairly bulky from what I gather, and I don't want a 4 spd. I don't mind cutting, as this cars going to get plenty of that anyway, but stock you have limited choices of seats as there is not much width for them, so wider in the tunnel area is not really preferred. I hear little to no talk of 5 spd trannies like the T-5 so not much info to be found. The car will be light (under 2400 lbs) so I can get away with one that wouldn't be strong enough in a Camaro or similar weight car. Can anyone provide insight as to options that won't get into big $$ that I can use? The cost of adapter kits seems to pretty much negate the savings over just using the T-56 from the research I've done so far. I'm open to sugestions to research more. Thanks in advanced.

ive got a world class t5 in my 65 mustang but i was planning on getting rid of it even when i had plans for just a mild 5.7 build; the tranny guys i talked to about it said it wouldnt hold up.

if it wont hold at 400 hp and 2800 lbs idk if itd work for what you want either

TKO is one option.

A company called G force upgrades T5's to be as strong as anything out there. But again expensive and from what I hear noisy.

You could probably run a world class T5. Just keep skinny tires on the car.

A lot of the guys putting 302's in MGB's are using the V-8 camaro T-5, and not compaining about problems, that's why I'm considering it as an option. I was thinking about a 302 at first myself as they fit good, but I can't stand the thought of using a Ford motor, besides the gen 3 motors are just so good and the Ford is getting too common in these cars for me.
I've also thought about the NV-3500, but they don't seem any stronger from what I can tell. I do plan on putting much wider tires under this thing than stock, probably an 8'-9' wide wheel, about 330-350HP (Starting with an LM-7 with a cam and headers) then maybe more later as I can afford to upgrade (hopefully swap from an iron block to alum block), and as light as I can get it within my budget.

You can look at the Richmond 5 or 6 speeds, They are pertty pricey but strong, might not be as common but are good transmissions.

You might be able to find a used one at a good price?

TKO 5 spd..

With the torque range of an LS1 in a light car you might consider a 4 speed. I assume you will be swapping out the rear axle so you wont be stuck with the Mgb 3.90 ratio. Depending on your tire size, you could run a 2.54 -2.73 rear end with a muncie or T10 2.6x 1st gear. The T10 was even offered in a 3.42 1st gear iron case if you want more off the line.
Other 5 speed OD options:
3550 (GM ones are kind of rare but priced right)
TKO 500/600
Mustang T5 with adapter bell housing and pilot bearing (easier to find than WC V8 GM T5s)
Keislers new RS trans (price looks good)
Richmond 5 or 6 speed (I love my 6 speed)

the richmond 4+1's can be had reasonably cheap and are strong as hell, but 5th is 1:1 and they shift like horseshit unless you have someone like brian at sk speed in lindenhurst go through it first.

i run one in my 67 camaro thats has the brian treatment with 3.73's and a 28" tire for driving around and its not bad at all on the parkway. love it.

I'm in this same boat right now. I think I've decided to bite the bullet, though, and get a decent trans (double $$ what I've got into my engine at this point!)

I'm looking at the Keisler RS400. I think it's a revised T45, with the weak points addressed and made to fit a standard bellhousing. The bare trans is about $1300. Works with a 4-spd bellhousing or they have a reproduction 621 bell for the LS engine for about $250.

Before ordering, make sure they can set you up for an LS motor.
The 400 still has the ford input shaft that you need their oddball clutch disc. And I think the 400 input shaft has a larger pilot bearing that wont work with the typical LS7 pilot bearing in LS motors.
The 500 uses a GM input shaft that eliminates those issues.