Bob Perkins
October 3, 2014

Correct Mach Tires

I have a ’70 Mach 1. I need to purchase a set of F70x14 white letter tires. What brand is correct for a Jan. ’70 Mach 1, Firestone or Goodyear or both? I’ve been told Goodyear by several judges. I personally like the looks of the Firestone better.

Billy Jones
Sweetwater, Tennessee

The Goodyear F70x14 Polyglas is the correct tire for your Mach 1. The Firestone F70x14 RWL (raised white letter) was first used on the Mustang in 1971 production, making the Firestone too late of a production change to be used on your Mach 1. I believe Mustang Club of America states this in their rule book.

Boss vs. HO Distributor

First of all, like you I too am a huge Boss fan. I bought my first Boss 351 at age 19 in September 1975 for $1,250. I still have it along with three others, including the third Boss 351 built in November 1970, a DSO (89) destination car. It was told to me at the time of purchase many years ago that this was the November 1970 Detroit Auto show display car. It is heavily optioned. I will include a copy of the window sticker for your personal information. I have never researched that information with Marti in Arizona. Simply because in the next several years I will semi-retire, get my cars out of storage, and start working on them. I have been collecting Boss Mustangs, a ’72 HO Mustang, a ’71 429 Mustang, and I have a ’70 Boss 302 you can see on page 13 of Donald’s Farr’s original Boss Mustang book. These are stored in insulated trailers. Anyway, I have been collecting parts aggressively for the last year. I still need a Boss 351 carburetor and a blue carb tag (like about everybody else).

I have two distributors with the wide band and two without the wide band. One of them with the non–wide band is on a Boss 351 engine that came out of a Boss car in the early ’70s that is complete down to the correct alternator and pulley, which will go in one of my cars. I have heard the wide band is correct, but I have a Boss 351 that I know came with the non–wide band. I have included a picture for your reference. Also, the non–wide band is D1ZF-12127-D. The wide band is D1ZF-12127-DA, as you probably know.

Butch English
Via the Internet

The D1ZX-BA replaced the D1ZX-AA sometime in November of 1970. The correct vacuum advanced for the ’71 Boss 351 is the wide gold band Autolite with square nose. The ’72-and-up vacuum advance is a type you pictured, which would be correct for the ’72 HO Mustang.

Boss Plugs

What is the correct Autolite spark plug for a ’71 Boss 351? I have conflicting opinions on which plug is correct, the AF 42 or AF 32, like those used in the Boss 302 and Boss 429.

Don Goebel
Evansville, Indiana

The factory recommended Autolite spark plugs are actually ARF 42s. These are resistor-type plugs (hence the “R” in the part number). I’ve enclosed a picture from the Boss 351 supplement that denotes the proper service parts for the Boss 351 engine, as well as the service specs for timing, plug gap, and so on.

Low-Gloss Black Formula

My brother and I just purchased a ’71 Boss 351. It is Grabber Green, but the hood accents, rockers, and taillight panel are painted gloss black instead of the flat or semi-flat that I remember. Could you give me a little guidance on the proper texture/paint mix? I’d like to touch this one up since it’s a driver, but also have the knowledge of what to do properly when the time comes to restore it. I can shoot paint, but will probably have it done just for expediency.

Dr. Ron Berges
Via the Internet

The original finish was low-gloss black with no texture. I would use the same type and brand of paint as used on the Grabber Green only in black with flattener added to achieve a low-gloss finish. I use the original PPG DDL-9423, but it may not be compatible with your paint system.

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Send your restoration questions to: Resto Roundup, c/o Bob Perkins, Perkins Restoration, North 2123 Hwy. 16 & 26, Juneau, WI 53039. Send email to