HotRod driveshaft yoke to transmission depth

[Shades]

Installed my driveshaft recently, and at first glance the yoke going into the transmission seems to have a lot exposed, and I was wondering if:

I need to move the engine back, or
I need a longer driveshaft (I confirmed it’s the correct one per the manual – 35” for SBC with 4L60e), or
It’s fine as-is

150321

Here’s the detail. Yoke is 4.5” long. When driveshaft is fully in transmission (bottomed out), there is 3/4” exposed, so that amount definitely can’t go in. I’ve read that you’re supposed to have 3/4 to 1” of free play for suspension movement, so 3/4” + 1” = 1.75” exposed would be a proper amount. I have 2” exposed when connected to the driveshaft at ride height, which means 2.5” is engaged. Ideally I guess it should be in 1/4” more? Is it worth messing with the engine mounts for that? Note that I only have 5/8” between the firewall and the distributor, so while I could go 1/4” back, I wouldn’t want to go much more.
150322150323

One topic at a time, but I do have a pinion angle issue also. The differential is angled 3.2° downwards (looking forward), and based on other posts here it seems I may need longer upper control arms to angle it up. I will reach out to FFR, but I’m thinking if I do that, there’s a good chance that will shift the driveshaft forward a bit, maybe about the 1/4” I’m looking for. (I may be wrong; it may move it further out, or just pivot and stay the same distance.)

Total newbie here, so checking in with the experts here. Am I on the right track? Is 2.5" engagement in the transmission sufficient?

[RoadRacer]

I'd say that's enough for driveshaft.. And are you sure you're at correct ride height? In my experience You have to be sitting at perfect ride height before the angles all start working. I thought I had issues being close to running out of adjustment (3 link) but when set to ride height f/r it all set up perfectly. I did have to add spacer under transmission admittedly but that's it.

[Shades]

Yes, I've measured and adjust ride height several times, currently 4-5/8” front and 5-1/4” rear. When measuring the pinion angles, I used a laser level to adjust for the slope of my garage floor putting wood under the rear tires so that the car is sitting on a completely level surface. Other than the weight of the body and no gas in the tank, I'd say it's as close to ride height as I could get.

[RoadRacer]

For what it's worth - and everyone will be different because of wheel/tire combos - I wanted as low a car as possible but I've had to keep raising it to stop tires hitting the body. I'm currently at 4.5" front, 6" rear. I'm running 285/35r19 tire, so do the math and see if you'll need to raise the rear too. Many factors to consider but wanted to mention it.

[Shades]

Thanks. I went with 285/35R18 on the rear, so an inch less height than you, and within the recommended specs. My spring adjuster is at the top of the threads though so I wouldn't be able to adjust any higher using the upper suspension holes. There's always the lower holes if I need them. Definitely a watch-out since that would probably alter the angles also.