When i first built my 502 i could see that the front gearbox tops were weak so i did a little mod (as per pic below)
I cut a small piece of hard brass, cut and bent it to shape and fitted 2 longer screws through the shock tower and threaded into the brass. This worked as a strengthener and supported the 2 lugs in which the shock tower bolts to.
Ive run the car now over 50 times both indoors and out and ive yet to break it, and it has taken a real beating.
If anybody is interested i can supply a few more of these for around £8 each. P.M me if interested and ill get a batch made up near the end of the week.