Convert to 5-spd, or build up a stock Type I?

[Jopapa]

Well I finally picked up the '74 Beetle I'm buying, and the guy had an extra transaxle that he was originally going to do a performance buildup with before he ended up having to sell the car. I'm wanting to do a mild performance build on the engine (good street, better highway), with mileage being a priority, since I plan to make frequent 300 mile drives back home over the mountians with it. I'm wondering if I'd get more bang for my buck if I put in a 5-spd tranny, or if I kept the extra tranny and did a performance build on it, with a Superdiff and whatnot? Thought/suggestions?

[Travis S]

Unless you are making more power you don't need to beef up your tranny, and unless your making more power a 5spd is useless becuase the engine won't have enough power to use 5th gear without running the risk of overheating. I think the best chocie would be a compromise, a 4sp freeway flyer transmision, somthing like a 4.12 and a .89 and a 1776 engine. The engine can be picked up for around 1.2-1.5k and the tranny for around 400. I think that would be a good combo

[Marc]

The "freeway flyer" term isn't tightly defined but I know of nobody who'd apply it to a 4.125x.89 combo (that's stock for any `67-`72 Beetle). A .82 4th from a bus would qualify with that R&P, as would a .89 4th in a 3.875:1 box.
I run a stock late trans in my driver (3.875x.93) and with 24.2" tall 195/60-15 tires it yields 3000RPM @60MPH, 4000RPM@80MPH, etc. - taller stock-size tires would make ~5% difference.
I'm currently planning to build a "compromise" street/strip 4-speed with a 1.39 3rd and 1.09 4th - that'll take ~3700RPM to go 65MPH with a 25" tire. IMO that's about the best you can do for performance and still remain streetable with only four ratios, it doesn't really fill the bill for your needs unless you bolt on some 26½" tires every time you hit the highway for home.
As you probably know, 5-speed conversions like Berg's use a stock 4th gear as 5th so there really should be no concern about it being too tall. Converting your trans to a 5-speed will set you back about $2500.

I guess if you live in some alternate universe where a good 1775 runs <$1500 you'll also be able to get a decent trans for $400. In my world those numbers are low by half.

[effvee1]

I beleive if you are making a freeway flier, than your rpms must go down. It will not be a block to block racer. In my 1973 Super when it was running I had a stock 3.88 ring and pinion, when this car shifted into second it was very strong in pulling thourgh out the rest of the shift points. But when I say freeway flier I mean lower rpm. This was not the case, I often did 85mph, and this speed would continue for apporx one hour. I could tell whenever I removed my foot from the gas pedal it was like douwn shifting, well you could tell the engine and trans were working harder due to the trans needing another gear. And this was with 65 seriers tires. So if your car will be a freeway flier, than your rpm must go down, when I get back at it I will install a 3.44R&P the other gears will be from a program for gearing. When your car is running and it needs a taller gear it really works the engine. If you get caught in traffic abruptly it will be very hot, this was even with a 914 fan installed for a type one dog house.