Using the same gauges as with E there definitely is a backbow on the neck.
Here's a chart I use for my Rickenbacker (33.25" scale). The standard ric gauges are different from what's "normal".
Code:
String Scale Length (in.) Pitch Gauge Tension (lbs.)
1 33.25 G2 0.045 40.9
2 33.25 D2 0.055 33.8
3 33.25 A1 0.075 36.3
4 33.25 E1 0.105 38.5
Total tension: 149.5 lbs.
String Scale Length (in.) Pitch Gauge Tension (lbs.)
1 33.25 F2 0.045 32.5
2 33.25 C2 0.055 26.8
3 33.25 G1 0.075 28.8
4 33.25 D1 0.105 30.6
Total tension: 118.7 lbs.
String Scale Length (in.) Pitch Gauge Tension (lbs.)
1 33.25 F2 0.050 40.5
2 33.25 C2 0.060 32.6
3 33.25 G1 0.080 31.9
4 33.25 D1 0.110 35.1
Total tension: 140.1 lbs.
First table is standard E with the standard gauges.
Second table is DGCF with the standard gauges.
Third table is DGCF with +5 gauges.
This is the reason why I always use a rule of thumb of +5 gauge upwards with DGCF.
The overall tension is fairly equal to the standard overall tension on E.
You can also see why you need to adjust the truss rod if you use standard gauges with DCFG, because the overal tension is lower, thus the truss rod tension should be lessened (usually about a quarter or half of a turn).
Although this is made for my rickenbacker using stringjoy strings, the same applies for other strings with 34", it just changes the numbers.
How did I change my tuning on the rick? Well, it was tuned in E when I got it. So I changed one string at a time for the new gauges tuning it in DGCF, one at a time. This way there's virtually no change in the overall tension on the neck and in effect I didn't need to adjust the truss rod at all.