JCS;
I do not have a Cobra,drive a 65 Fastback GT-350 (clone),351-W,350 hp,5sp,3.00 rear gear..... This car was built to be a street car,a few years later I started drag racing at the strip,had fun,enjoyed it a lot,did fairly well,now I road race,actually open track,working on my competition license,been to a few weekend driving schools,enjoy it more than drag racing.... Still drive my car to work (250 miles daily) at least twice a month,get 22 mpg on the highway,idles at 180 degrees in traffic all day long.....Love it would not change a thing,except for maybe a little lower rear gear.....
This past weekend I was in Nashville for the 40th Mustang Anniversary,ran the open track friday and saturday,had a ball,ran great times..... With this fully street legal car with a full interior and weighing in around 3100 pounds I ran laps of 1:23/1:24 all day with a best of 1:22...... They had a Vintage race (actually 3 races) for the 65/66 GT-350's,real race cars,not anywhere street legal,most weighed in at 2400 to 2600 pounds,the slowest of the field was turning laps in the 1:17 to 1:18 range!!!!!!!!!!!!!!!!! I was 4 to 5 seconds off that time in a fully equipped street legal and street driven car,I could not believe it........
Point is you do not need killer hp to be fast,good set-up,handling and tires will get you further than a lot of unusable hp.....A number of years ago I drove a "bone stock" FFR,302cu. in.,250 hp, and this car suprised the hell out of me as to how quick it was and how quick it reacted.....Go drive an FFR spec racer and you will see what I mean.....
All the advice is right on from people who have been there,done that................
On the tranny subject,I recommend the Tremec,seen too many Mustangs blow up T-5's with 300 to 375 hp.,I think the Tremecs are a lot less than your quote,I think they can be had for around 1200 to 1300 right now,my Tremec has over 21,000 miles on it with about 50 passes on the drag strip and at least 250 miles on the road courses,no problems,has always shifted perfectly,have only changed the
oil in it once,last year,probably should do it yearly......It is worth the extra money over the T-5 to me,especailly if you blow up just one T-5.........
David