This is a Starter extension for the LS3 Chevy Engine (https://www.thingiverse.com/thing:1911808).
The starter Drive Gear is a remix of the original.
The electric wires connected to the solenoid are factice.
The electric wires connected to the body must be must be connected to the jack.

My finished project : https://www.thingiverse.com/make:743429

Printed parts list (5)
1 x Starter_Body : Layer:0.15mm Raft:no Brim:no Support:yes Infill:50%
1 x Starter_Cover : Layer:0.15mm Raft:no Brim:yes Support:no Infill:100%
1 x Starter_Drive_Gear_Remix : Layer:0.15mm Raft:no Brim:no Support:no Infill:100%
1 x Starter_Mount_V2 : Layer:0.15mm Raft:no Brim:no Support:yes Infill:100%
1 x Starter_Plug : Layer:0.15mm Raft:no Brim:no Support:no Infill:100%

Accessories (30)
2 x 3mmx20mm threaded rod
8 x m3 jam nut
4 x m3 washer
4 x m3 lock washer
2 x m3x12mm SHCS
2 x m3x35mm SHCS
1 x male jack : https://www.amazon.fr/Rtengtunn-dalimentation-Ensemble-Connecteur-Adaptateur/dp/B08D9DBXHB/ref=sr_1_9
4 x electric connector
1 x braided sheath
1 x 3mm electric wires
1 x Electric motor : https://www.amazon.fr/gp/product/B07RRPS7CC/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

Assembly
Look at pictures.

Release
02/07/2020 The file Starter_Mount.stl is replaced by Starter_Mount_V2.stl ;
It allows lateral adjustment of the electric motor.

More add-ons

https://cults3d.com/fr/collections-de-designs/dancan13f/chevi-ls3-engine-add-ons