I have a Pro4 SC10 and a Tenacity TT Pro. Unless I’m mistaken, the c-c lengths for the Pro4 shocks are 94 and 108 mm, and the Losi shocks are 90 and 110 mm. You’ll want to shorten the Losi rear shocks with internal limiters and use longer shock shaft eyelets in the front to get the droop right.
It might be you want to reduce the droop a little but 4 mm shorter front shocks is stretching it. (Depending on the mounting holes you choose, front droop can be limited by the steering links. The ball ends don’t have clearance for large angles. This is not good, put some limiters inside if this happens.)
The Pro4 shocks have very thick external limiters, 8 mm. There’s very little uptravel and the truck could use some but the stock shocks bump the pistons against the bladders if you reduce the ext. limiters.
Both shocks are plagued by undersized pistons. The Losis are aluminium but the quality of them isn’t that high, they are definitely RTR-grade shocks. If you are spending money to buy better shocks I think it would make sense to go for a more significant improvement. The AE shocks that come with the racing-grade kits are expensive but you get what you pay for.