I am looking at beefing up the drive shaft and rear end in my drag car and wanted to hear opinions.

What is the car?
1970 Satellite 440 footbrake/7.0 index 1/8th mile car
Current HP roughly 450 with plans to go to 550 HP over the next two years
Car weighs 2860 lbs empty and 3100 with me in it
Using Hoosier 29x9.0 radial drag slicks
Current set-up is an 8 3/4 489 w/4.88 gear stock posi unit
Drive shaft is stock
Pinion snubber
Stock springs
Stock axles

Options:
I have another 489 w/4.56 gear on a spool
I also have an empty 8 3/4 housing
I am thinking of building this and adding Calvert racing springs & Caltracs
If I did this, I would buy next Strange axels and probably upgrade the yoke to a 1350

My second choice would be to simply buy a new Dana set-up from Strange

Obviously the second option would be more expensive, but since I am planning to change the springs to Calvert and upgrade the yoke either way, I wondered should I build the 8 3/4 or not?
The advantages I see to the 8 3/4 would be:
1. Weight
2. Cost
3. Flexibility in changing gears, (this does matter as I usually run 1/8th mile, but would like the option of running a 1/4). If I bought the Dana, I could always keep the 8 3/4 I have and put a 4.10 gear in it for 1/4 mile runs. IS it easier to swap the center chunk from an 8 3/4 or swap the two setups out all together?

It comes down to either spending the $700-$800 on the axles and yoke for a 8 3/4 or using this money towards buying a Dana.

The question is, How would you compare a 489 8 3/4 with a 1350 yoke and spool and Strange racing axles to the Strange Dana?

What would you do?