I am looking at picking up a 914 and turning it into a track/autocross car. My questions are high level. If you can assist with any or all any assistance is appreciated.

Body
Fenders - Plan to go wide body to fit larger tires, recommendations/pros/cons ? Metal/fiberglass?
Floor Pans - they don't look bad, but I saw somewhere that you can replace them with deeper ones for sitting lower, i'm tall so every inch counts.
Braces/stiffing - full cage or something in the rear tied into shock towers and something in the front tied to shock towers
roll cage - needed? recommended? custom or weld in off the shelf?

Suspension
Front Hubs - do you upgrade replace these, someone told me swap with 911
to get 5 lug?
Coil Overs at the corners? recommendations?
Sway Bars? Torsion Bars?
Upgrade rack and pinion?

Fuel system
Fuel Tank - Assume being a 50 year old car to redo the fuel system and get a fuel cell with integrated fuel pump and braided lines, any recommendations?

Transmission
Keep or upgrade from a 911 or similar to handle more power? Hoping to get 300+ in the motor

Braking
If I upgrade to 5 lug, then i assume there is a prefered brake upgrade from a 911 for more stopping power

Steering Wheel
Its not in the center of the driver seat, have people moved it to be more centered?

Dash
if I move the steering wheel i assume this gets redone with new gauges etc.

Front lights
i'm thinking or relocating to the bumper and getting a solid frunk with no holes for lights. Cleaner looking

Targa top
I would assume you can't race with this on so do people ditch it altogether?

Motor
swap a 6 or go nuts and do an LS?

Thanks,

Really you want to make modifications from a different perspective if you intend to race or compete

As a street car. Do what you want
But as a competition car it’s easy to make a change that puts you into a higher class where you can’t compete or possibly won’t be eligible at all to run in that series


You want to use the rule book to dictate what is legal
You want to pick the classification within the club and then what modifications

Pick your club

Visit the club
Talk to other competitors in the events
Then decide the class and use the rule book

What Brant wrote. Fairly sure that 300hp will require major chassis strengthening and upgrades. Gear box too. Maybe CVs. Deep well.

As said, build to whichever rule set that the sanctioning body you'll be competing in uses.
Then, what is your budget?

When you've sorted those two, here are some resources.

Cage - Autopower is budget friendly. You'll have to add on for your suspension point pickups, but their basic cages are sound. Otherwise there are custom fabricators that can build to any spec you want. If you were in this area I could recommend a few.

Brakes / suspension (5 lug, etc) PMB Performance

Suspension - Elephant Racing

Transmission - California Motorsports

Engine - depends on which way you go but for 4 cyl European Motorworks for parts and machining, for a 6 you can't go wrong with a Rothsport built engine, for LS I have no idea..

For us tall guys (i'm 6'4" you'll probably have to go speedster style (no roof) so the main hoop of the cage can be higher than the original roofline / Targa bar. Look up "Ginther 914" and you'll see what I mean. My car is done this way. Yes you can / should race with the top if you choose to keep it.

Mine has an ATL Sp 115 fuel cell, external electric pump.

Thank you! I'm 6'4 as well. I sat in an empty tub yesterday with the factory seat not bolted to the floor and was suprised i didn't touch the targa top, i imagine i would with a helmet. I also figured the seat could be mounted lower and i have even seen a floor pan with an inch drop in it for extra clearance. I am in the gathering information phase so appreciate the feedback. I was mainly thinking along the lines of autocross or road racing. Still looking for rule books for the different sanctioning bodies and comparing what is available close to me (Houston Tx)

Look up CVAR

You can run a 914 on lots of tracks with those rules

But not the v8. As it is a vintage club

In general the 'broomstick" rule is that if you held a broomstick from the top of the bar to the top of the next forward bar or other structural member (A pillar and top of windshield frame don't count) you need 2" clearance between the top of your helmet and the underside of the broomstick.

You are forgetting one critical piece that will drive all others for the suspension.

Tires!

The setup for a 200TW tire is way, way different than a DOT-R tire. That will be one of the main drivers in spring/torsion bar stiffness.