When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
OK, so I thought I'd go ahead and start a build thread. I'm currently a little over a year into it and have no expectations that it will be done this year ( LOTS of mods, fabrication and thinking required, plus I run my own shop restoring and repairing British cars, and it's side project for myself). I have a 1971 MGBGT and it it getting an LS-1/T56 combo from a 2002 Trans-Am, with a BMW E36 IRS as well as the BMW's front spindles and brakes.
I will over time catch you up to where I'm currently at on the car. Here's the car
going into the shop for surgery
I've been thinking about this project for many years, so the initial test fit was mostly to see if my plan of attack was feasible or if I needed to re-think how I was going to do it. It all looked about how I envisioned so no major changes to my plans at this point. Of course in this pic it's not all the way in as the damper is sitting on the steering rack
After moving the steering rack out of the way as well as trimming the firewall a bit and cutting part of the crossmember out ( not planning on using it anyway) it goes all the way in. Where its sitting the shifter falls right in the center of the factory MG shifter hole.
The engine bay is very tight, but I knew it would be. The plan is to make room by widening the car a little and reshaping the front rails and inner fenders to hopefully get long tube headers inside the rails while giving all the inner structure a plausibly factory look when done.
Back in the late 80s I worked in a speedometer shop and a guy brought in a MGB with a early 60s Buick all aluminum V8 shoehorned in there, according to him it was a common swap, that car was crazy fast. I'll be watching this thread.
MGB with a early 60s Buick all aluminum V8 shoehorned in there
The MBB could be had from the factory with BL's version of that aluminum V8. GM sold the rights to the little 3.5L alum V8 to British Leyland who used it in a bunch of vehicles for many years --- eventually punched up to 4.6L in various Land Rovers over the years. Below is part of the Wiki on the MGB V8.
MGB GT V8
MGB GT V8OverviewProduction1973–1976Body and chassisBody style2-door coupePowertrainEngine3.5 L RoverV8MG began offering the MGB GT V8 in 1973 utilising the ubiquitous aluminium block 3,528 cc Rover V8 engine, first fitted to the Rover P5B. This engine had been used in the unibody GM 1961–1963 A-body platform Buick Special/Skylark and Oldsmobile F-85 and 1961–1962 Pontiac Tempest and was the lightest mass-production V8 in the world. The Buick version had a dry, undressed weight of 318 lb (144 kg) and the 1963 Skylark with optional four-barrel Rochester carburettor and 10:1 compression ratio produced 200 hp (150 kW) at 5,000 rpm. By the time Rover had made webbing modifications to strengthen the block, the engine was considerably heavier (over 170 kg). Some changes were made by MG-Rover and the engine found a long-lived niche in the British motor industry. These cars were similar to those already being produced in significant volume by tuner Ken Costello. MG even contracted Costello to build them a prototype MGB GT V8. However, the powerful 180 bhp (134 kW) engine used by Costello for his conversions was replaced for production by MG with a more modestly tuned version producing only 137 bhp (102 kW) at 5,000 rpm. Nonetheless, 193 lb⋅ft (262 N⋅m) of torque helped it hit 60 mph (97 km/h) in 7.7 seconds and go on to a 125 mph (201 km/h) top speed. Fuel consumption was just under 20 mpg.[26]
MGB with a early 60s Buick all aluminum V8 shoehorned in there
The MBB could be had from the factory with BL's version of that aluminum V8. GM sold the rights to the little 3.5L alum V8 to British Leyland who used it in a bunch of vehicles for many years --- eventually punched up to 4.6L in various Land Rovers over the years. Below is part of the Wiki on the MGB V8.
MGB GT V8
MGB GT V8OverviewProduction1973–1976Body and chassisBody style2-door coupePowertrainEngine3.5 L RoverV8MG began offering the MGB GT V8 in 1973 utilising the ubiquitous aluminium block 3,528 cc Rover V8 engine, first fitted to the Rover P5B. This engine had been used in the unibody GM 1961–1963 A-body platform Buick Special/Skylark and Oldsmobile F-85 and 1961–1962 Pontiac Tempest and was the lightest mass-production V8 in the world. The Buick version had a dry, undressed weight of 318 lb (144 kg) and the 1963 Skylark with optional four-barrel Rochester carburettor and 10:1 compression ratio produced 200 hp (150 kW) at 5,000 rpm. By the time Rover had made webbing modifications to strengthen the block, the engine was considerably heavier (over 170 kg). Some changes were made by MG-Rover and the engine found a long-lived niche in the British motor industry. These cars were similar to those already being produced in significant volume by tuner Ken Costello. MG even contracted Costello to build them a prototype MGB GT V8. However, the powerful 180 bhp (134 kW) engine used by Costello for his conversions was replaced for production by MG with a more modestly tuned version producing only 137 bhp (102 kW) at 5,000 rpm. Nonetheless, 193 lb⋅ft (262 N⋅m) of torque helped it hit 60 mph (97 km/h) in 7.7 seconds and go on to a 125 mph (201 km/h) top speed. Fuel consumption was just under 20 mpg.[26]
Lots of Ford and Chevy V8's also transplanted into MBB's over the years -- Cobra paved the way.
The engine bay is very tight, but I knew it would be. The plan is to make room by widening the car a little and reshaping the front rails and inner fenders to hopefully get long tube headers inside the rails while giving all the inner structure a plausibly factory look when done.
You can pop out the heater core bungs and tap for angled fittings. Take a look thru any of the C3 corvette swap threads, they all have to overcome that problem.
I dig the unique swaps, very cool!
This is both a conversion and a restoration at the same time as this is a pretty rusty car. Some will wonder why I'm using this one and not a more solid one, but there are several reasons why I'm not starting with a better example. This particular car came from a good friend who wanted to be a part of this project, but unfortunately passed away before it could get started. Using this one makes him a part of it in a way, plus the rockers, floors and other rusty areas are going to get cut out as part of the modification process regardless of the condition they are in so the rust doesn't bother me. I didn't want to cut up a good car in case I got in over my head and couldn't pull it off. That said the car turned out to be a bit rustier than anticipated, which did change how I tackled it and in some ways actually made it easier as I didn't kill myself trying to save some bits. Of course, the car being built the same year I was helps too make me want to stick it out.
This is going to be radical. At the shop I work at we cater to a lot of British cars as well, the midget on our frame jig is just begging for a similar swap treatment.
Those under 40 may not get the Ginsu reference, but I thought it appropriate for this project. Actually I ended up doing even more cutting than I originally planned due to rust I found behind the heater in the firewall, but I think it will be a better finished product because if it.
On to the start of the fun stuff, the first cuts on the body.
The plan is to widen it a little to gain some room in the engine bay to get headers inside the frame rails, to give give me a little more room for the cage without encroaching so much in the drivers compartment and quite frankly, to do something different that no one else has done. I don't want to use custom glass so cutting through the a-pillars was my solution. I'm limited in how much I can add there though as too much will make the car look odd, so I figured I'd split it and try out different measurements taping the pullers and seeing how much just doesn't look right anymore figuring 1 1/4 would likely be all I can go per side. In the end that was as much as I figured I could make look right.
^^^ what he said... seriously impressed with the widening of the body.
I have good memories of the MGBGT. My old school mate had one with a blueprinted Shelby spec'd 302, toploader 4sp and a 9" diff conversion. It got 30mpg, ran 145mph with the gearing it had (got there fast) and handled exceptionally well for the time. It was a great car and we had some tremendously fast trips in it (he was a cop so drove it like he stole it and knew where the other cops were). An Ls1 will be even lighter than the little 302 with alloy heads - good conversion!
02-13-2019, 01:51 PM
LS-1 MGBGT aka "Project Ginsu" 
