Join Date: Mar 2005
Location: Twin Cities, Minneapolis
The cheap 70mm journal that comes with the kit was a great turbo for my stock block 347. If reliability is an issue, the 70mm is relatively dirt cheap to slap a new one on. It’s literally 4 volts, that are easy to reach. To swap a T4 turbo on a Fox On3 car is at most a half hour of easy work.
People go with larger turbos for a number of reasons. More power, less back pressure are the 2 most common reasons. But there are also downsides to going larger. Fitment and being more lazy are 2 common downsides. There are ways around those issues. But for your build it’s pretty much a simple build. The basic 70mm journal is cheap and sized pretty well for your build.
When you move from your 331 into an aftermarket block. Then start trying to over think it. For now, there is no valid reason to create a mountain from a mole hill.
For injectors, I went with Injector Dynamics. I needed high Z’s.
There are a slew of 80# injectors on the market now and they are low buck. Mine were nearly $2k but drastically overkill for your build.
I’d look for a deal on some Ford 80’s and call it a day.
The basic On3 kit is a solid starting point. Don’t worry, it still packs enough to split your block in 2 with relative ease. Save your money in upgrades and spend it elsewhere on the car. Transmission, rear end...suspension, tires, ECU, fuel system...the list never ends.
1993 Teal Cobra #2531 1 of 452, 347, Precision 7675, The entire kitchen sink....maybe 2 kitchen sinks at this point!