I just did a similar swap using Larry's recommendations. It went perfectly. I was unable to locate the bracket that was recommended. I ended up going to a local parts yard and the had a pile of brackets laying there. I picked out two 'possible' substitutions. I ended up
using one on the front and one on the back.  The car is much happier now.
Robert
1978 MGB

From James Nazarian Jr March 2002

Larry,

Thanks for the help.

I have some comments for your conversion page.

I bought a NAPA alternator for a 83 camaro 305CI V8.  Lifetime alt was part #RAY 13-4010, I say this because it has American threads. 

On my '71 I installed like yours but used one 5.5" bolt through rear hole on block, through a tube, through water pump hole, into alt ear, tightened and then bolted just for good measure. 

On the bottom, I just couldn't get the universal 'j' bar to fit.  I put two more inches of bend into it, put the stock fixing bolt into the hole nearer the bend.  Then with my new bend I used a 3" bolt through the thick ear on the alt, through the slot in the bracket and bolted.  I had to change belts to accommodate this since my old alt was pulled in all the way and still tight.  The belt I used was 39 5/8" long and 25/64 wide.  It put me near the minimum of my new travel.

Parts (Napa jobber prices):

Time: ~1hour if I had measured right for the first fan belt.

James

From Ernie Higgam June 1999

Larry,

Conversion is done, works great! Refined your procedures just a tad. On the bracket/brace to the back of the alternator, I recommend that the old mounting bracket on the block be turned upside down and the mounting whole perpendicular to the side of the block (where the old alternator rear mounting bolt went) used as the attachment point for the new rear brace to the engine. Changes the angle that the brace takes to the block. It offers three benefits; better clearance between the brace and the rear of the alternator, the angle between the two increases so there is more support to negate the "front/rear" motion of the alternator which could snap the water pump mounting point, and there is some adjustment allowed because of the two oblong mounting holes in the bracket where goes to the block. With the thickness of the bracket used and the mounting points/angle, you could probably pull the engine with a strap around the alternator! She's not going anywhere.

FYI, if folks can find it I used the following alternator arm for both pieces (front adjustment and rear brace). DAYTONA by Mr. Gasket; Part No. 9851 Cost me $12.00.

Once it is cut to the proper length for the front adjustment bracket, there is more than enough straight stock left over to use for the rear brace. Made a template of the rear brace with a  hin piece of tin and had a local machine shop do the cutting, drilling, and bend the rear brace for me. They charged a whopping $10.00. Another mod I made was to have the hole in the brace which goes to the back of the alternator oblong so that if there is a need to adjust the alternator, both front and rear brackets have enough room to move. Wish I had a means to send a sketch of how the rear bracket was bent. Let's try and "visualize." Basically the part to the bracket on the block had about a 30 degree angle at about 1" from the end, bent towards the "front" and the end that goes to the back of the alternator had a reverse bend of about the same angle leaving about 2" so the oblong hole could be drilled.

Total Costs:

Still well under a replacement rebuilt "Prince of Darkness" and about 25 amps more on the output.

Aside from machine shop, total time was only about an hour!