TH350 or 700R4 vs 200R4

[Carlos]

Hi
I am running a cobra replica ( sorry no Buick, yet ) and think about changing tranny.

Total weight of car is around 2.600pounds incl fuel and driver.

Engine is a modified SBC ZZ3 with Weber48 Carbs,TRW pistons CR 11:1, ported heads,Crower cam 471LM, MSD 6AL ignition.
Tranny is: a TH350 with shift kit
Converter is a B&M 3000 stall
Rearend is 3.07 on 275/60/15 Tires.

Main purpose of car is cruisn around, however I went to the strip once and is was fun as well, will go there occationaly.

As my cuisin speed is around 60-80miles and I am going long distance on the Autobahn ( 100-130+mph )I need to bring down RPMs. Think about gas price over here 4.98$/gallon...

Although my current combo as listed above was not even too bad on the 1/4 mile (time slip see below ), I think about replacing the TH350.
Thought about swapping rear end by a 2.88 and adding 700R4, but some folks suggested a 200R4. !?
The rearend change mainly is planned because the pwrlock of 3.07 is damaged and the 2.88 is sitting there ready for goin' in.

Not sure which way to go.

Would apprecciate any feedback.

Thanks

C.

60ft time 1,880
1/8 mile time 7,701
1/8 mile Speed 89.2mph
1/4 mile time 11,999
1/8 mile Speed 113,2mph

 

[bruce]

If you can get a GN 200R4 or update to one, then that's the ticket.

The gearing spread is nice, and has an OD. The 3.06 1st gear of the 700 is neat for impressing folks with wheelspin, in first gear, but little else, IMO.

 

[CopGn]

I would do a 200 R4 because you have a closer gears for racing. If you can hook real good I would go with a 3.55 rear gear and not any higher. This would give you neck snapping acceleration in any gear. By the way I owned an incredible replica so know a thing or two of the cobra dynamics.