Tire sizes

[AC Ventura]

In the UK we use 225/65/70 R15 Avon CR6 ZZ. Nice high profile and same diameter as the 275/55's on the back. My application is an Autokraft Mk IV. No rubbing issues at all, but obviously depends on offset and your cars clearance.
It's simple enough to find the width and diameters of your existing and proposed tyres. Then make thin wood template and run it around the tyre at full lock. You'll soon see if there's any fouling issues. That's exactly what I did.

[cycleguy55]

Currently running 245/60R15 up front and 275/50 in the back. Almost certainly going to go with 245/60R15 front and 275/60 rear when it comes time to replace them. Worth noting is that I have power steering, so the wider tires aren't an issue as far as steering effort goes.

[t walgamuth]

Originally Posted by cycleguy55

Currently running 245/60R15 up front and 275/50 in the back. Almost certainly going to go with 245/60R15 front and 275/60 rear when it comes time to replace them. Worth noting is that I have power steering, so the wider tires aren't an issue as far as steering effort goes.

What kind of ps are you running? How is the road feel? Will it return itself when you let go of the wheel?

[cycleguy55]

Originally Posted by t walgamuth

What kind of ps are you running? How is the road feel? Will it return itself when you let go of the wheel?

Mustang II PS rack, Saginaw PS pump - modified with both flow (2 GPM - many available) and pressure reduction (Borgeson 899001 kit). If I did it again I'd probably use an adjustable valve like the Heidts Adjustable Power Steering Valve (PS-101). That way you could dial it up for autocross and dial it back down for regular use.

The pump is mounted with a billet aluminum bracket from CVF Racing, and the PS pump pulley is from CVF as well. The crank pulley is from March Performance (it was on the car when I bought it in 2014).

Road feel is okay, not great. Self-centering is not great either, but I haven't taken it back in to have the caster increased - it's still set low for manual steering and needs to be dialed up for the PS.

BTW, I don't make a habit of letting go of the steering wheel!

[t walgamuth]

Originally Posted by cycleguy55

Mustang II PS rack, Saginaw PS pump - modified with both flow (2 GPM - many available) and pressure reduction (Borgeson 899001 kit). If I did it again I'd probably use an adjustable valve like the Heidts Adjustable Power Steering Valve (PS-101). That way you could dial it up for autocross and dial it back down for regular use.

The pump is mounted with a billet aluminum bracket from CVF Racing, and the PS pump pulley is from CVF as well. The crank pulley is from March Performance (it was on the car when I bought it in 2014).

Road feel is okay, not great. Self-centering is not great either, but I haven't taken it back in to have the caster increased - it's still set low for manual steering and needs to be dialed up for the PS.

BTW, I don't make a habit of letting go of the steering wheel!

Do you have a rough idea of the cost of it all? ...going from manual to power?

[cycleguy55]

Originally Posted by t walgamuth

Do you have a rough idea of the cost of it all? ...going from manual to power?

Not really. The car came with PS but that was removed when a replacement water pump turned out to be roughly 1/2" longer. Ford produced the shorter version for only a couple of years and, IIRC, only for Lincolns. When I installed the longer one the alternator lined up better than it was before, but the poor PS alignment became even worse. That, and the fact it had badly cobbled-up bracketry made for an easy decision to remove it. After doing that I had the front end re-aligned to reduce the caster and drove it for a season.

After that season I found myself looking at options to put the PS back on and found CVF Racing and what they had for brackets and pulleys. The old pump was usable, but the pulley had to be replaced as it wouldn't have lined up properly. The earlier water pump replacement was actually quite fortuitous, as all the after-market brackets were built for the longer water pump. My total cost for the PS bracket and PS pulley was $171, plus shipping. I also changed the alternator fan and pulley at the same time, though later converted to a 3G alternator with internal fans.

Saginaw PS pumps, Mustang II PS racks, valves and plumbing are widely available. CVF offers their own PS pumps and they're reasonably priced ($150-160). They have a full line of serpentine conversion kits, brackets and accessories for SBC at https://www.cvfracing.com/chevy/smal...7-305-350-400/ I would have gone with serpentine instead of v-belts, but there was nothing for my alternator installation that would fit - a SBC could be quite a different matter.

[w-lewis]

I decided to go with 235's in the front.

[t walgamuth]

Thanks Brian! There is a good bit of great info there. Is there free play at TDC on the steering wheel?

I have a fat man front end on my 39 Studebaker with the mustang 2 based front end and it has about an inch of free play at the top. I wonder how different the Miata rack is in construction, the feel was a lot better than the Stude is.

[t walgamuth]

I got my power steering working pretty well now. I was able to get 4 degrees caster in it and it has better more settled feel now but still very sensitive. Perhaps the 2.2 turns lock to lock is too quick for the street.