hey, since that kenney leave or something, I'll trie to make a similar tuts like he did.
first of all heres wut u will need:
ur gen1 chassis
4 screws
2 plastic bearings (optional)
2 plastic lug nuts (optional)
philip screw driver
X-acto knife or hobby knife
a piece of plastic
STEP 1
first of all cut two small pieces of plastic like those about a inch for 1:25 scales longer or shorter depending ur scale :
STEP 2
then lenght the right lenght between ur chassis and ur rear deck (depend on ur model)and drill the holes.:
STEP 3
Screw the chassis and ur rear deck together with those extended pieces:
Has u can see on the picture, i took longer screw and lug nuts so it can be hardened.
STEP 4
here we go u got an extend chassis enjoy!
Hope it help people!!