The Mustang Forum for Track & Racing Enthusiasts

Taking your Mustang to an open track/HPDE event for the first time? Do you race competitively? This forum is for you! Log in to remove most ads.

  • Welcome to the Ford Mustang forum built for owners of the Mustang GT350, BOSS 302, GT500, and all other S550, S197, SN95, Fox Body and older Mustangs set up for open track days, road racing, and/or autocross. Join our forum, interact with others, share your build, and help us strengthen this community!

Gen1 70 Mach 1 SCJ Drag Pack Build Thread Profile - Gen 1 Mustangs

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

6,394
8,273
I worked at this place off and on for about 25 years,(days off from the FD) great folks, The owner has a 67 and a 68 Gt500 mustang, a Gt350 (69) clone Sunbeam Tiger and we've worked on a million cars there. Dyed in the wool Ford guys. this si a link tot heir project page, if you are interested.

 
Last edited:
The item 70 Mach 1 SCJ Drag Pack has been updated:

Update 2/28/21
Engine is home!
428 SCJ, 30 over 10.5:1 TRW pistons, Comp cams hyd flat tappet, Stock shafts & adj rockers, Steel end support stands added, Ebock RPM heads & intake,
PRW alum water pump, Canton 7qt T-Pan (8 qts with the oil cooler). 427 valve covers are temporary - I have a set of 428 Snake covers on the way.
Scheduling some time on the dyno for break in and set up. Also trying to decide on fuel system: stock Holley carb (735) or Holley sniper EFI....
More to come....

428 SCJ -2   2.28.21.jpg

428 SCJ 2.28.21.jpg
 
Last edited:
1,118
1,722
Exp. Type
W2W Racing
Exp. Level
3-5 Years
Huntsville, AL
1,118
1,722
Exp. Type
W2W Racing
Exp. Level
3-5 Years
Huntsville, AL
Several of my vintage race friends use Siebert. Very good carbs. It will probably be my next carb.

I have two carbs from SMI before he got main stream and super expensive. Sean is the original product engineer for JET Performance Products. He is a wealth of NA knowledge and he still answers his own phone.
 
6,394
8,273
The item 70 Mach 1 SCJ Drag Pack has been updated:

Update 2/28/21
Engine is home!
428 SCJ, 30 over 10.5:1 TRW pistons, Comp cams hyd flat tappet, Stock shafts & adj rockers, Steel end support stands added, Ebock RPM heads & intake,
PRW alum water pump, Canton 7qt T-Pan (8 qts with the oil cooler). 427 valve covers are temporary - I have a set of 428 Snake covers on the way.
Scheduling some time on the dyno for break in and set up. Also trying to decide on fuel system: stock Holley carb (735) or Holley sniper EFI....
More to come....

View attachment 63029

View attachment 63030
I think I'm sporting a semi..
 
Oct 2021
Slow going on the build. Time is a commodity that there is never enough of.
Had a minor setback by choosing an RPM intake for the engine.
It was a late discovery that an RPM intake and a shaker hood don't mix well.
The RPM sits 1 inch higher and 1 inch back compared to OEM and hood wants to hit the rear of the shaker scoop. (GRRR)
I didn't want the bulk of a cast iron CJ intake and fortunately, a friend had a really nice aluminum PI intake he was willing to sell.
Some hairline cracks were notices on the flywheel and I ended up having a new SFI wheel match balanced. (Say "no" to 50 yr old cast iron)
Rear leafs turned out be the originals and were in decent shape so they were disassembled, blasted, painted and reassembled with new hardware.
Same for the staggered shock plates and sway bar brackets.
This part was much less of a hassle than I had anticipated. Although, I'm still finding media in strange places :oops:
Finish is not concours, but it'll do.
The rebuilt (date code) 4:30 "N" case center section was sourced from Allen at 8 & 9 inch rearends.
Once that was installed it was followed by the axles and brake hardware.
Just need to tweak the brake fittings a bit then I can slide the whole assembly under the car.
Dash wiring is probably next

20210926_170326.jpg
 
Last edited:
Oct 2021
Slow going on the build. Time is a commodity that there is never enough of.
Had a minor setback by choosing an RPM intake for the engine.
It was a late discovery that an RPM intake and a shaker hood don't mix well.
The RPM sits 1 inch higher and 1 inch back compared to OEM and hood wants to hit the rear of the shaker scoop. (GRRR)
I didn't want the bulk of a cast iron CJ intake and fortunately, a friend had a really nice aluminum PI intake he was willing to sell.
Some hairline cracks were notices on the flywheel and I ended up having a new SFI wheel match balanced. (Say "no" to 50 yr old cast iron)
Rear leafs turned out be the originals and were in decent shape so they were disassembled, blasted, painted and reassembled with new hardware.
Same for the staggered shock plates and sway bar brackets.
This part was much less of a hassle than I had anticipated. Although, I'm still finding media in strange places :oops:
Finish is not concours, but it'll do.
The rebuilt (date code) 4:30 "N" case center section was sourced from Allen at 8 & 9 inch rearends.
Once that was installed it was followed by the axles and brake hardware.
Just need to tweak the brake fittings a bit then I can slide the whole assembly under the car.
Dash wiring is probably next

View attachment 69247


Dec 2021
Rear is in and she's standing on all 4's again !
Aluminum Ford PI intake was swapped out to replace the RPM intake (interferes with shaker hood/scoop - who knew?)
Engine is T'd up for install - just need to bolt on the clutch & bell along with the exhaust manifolds.
After that its time to dive into wiring and brake/fuel lines....yay

20211120_131327.jpg

20211120_131419.jpg

20211120_131340.jpg

20211120_132911.jpg

20211120_142842.jpg

20211120_131859.jpg
 

TMO Supporting Vendors

Buy TMO Apparel

Buy TMO Apparel
Top