I am wondering which to do, or both.

I am also wondering if there is a point of diminishing returns, because of added weight and not much of an increase in rigidity....


But then my gut/instinct tells me this is a 1975 914 and it probably can use all the help it can get, and that the weight penality is easily worth the added rigidity.

Intended goals of the car, plenty of tire smoking torque out of a turbocharged Type IV and sticky tires + stiff suspension.

I am at the point of removing paint from the inner longs while I redo my pans and por-15 them. Since it is winter, doing some welding and having it down a little longer is no big deal.

I also am going to be installing the engman large plate front swaybar mount reinforcements since the sheetmetal there on the drivers side shows some fatigue/stress signs from some road debris smacking the underside of the chassis sometime in the past.....

Thoughts?

Engman first. Then if you need it, carefully analyze the components of the GT kit and only add what you need for your application. There are parts in that kit that only add weight with no structural benefit.

you missed the Brad Mayeur long kit too... I know of at least one person who runs engman and the brad mayeur kit for longs... it makes for a very stiff setup.

I really like the way the mayer kit ties the longs to the suspension

I started with a solid/rust free '74 chassis and put in the GT stiffening kit, longs kit from Brad Mayeur, full roll cage, front and rear stiffening with a 3.0 six and weigh just over 2300 lbs. wet. I didn't need the long kit, but wanted more support and the weight didn't matter. Removed the sound pad behind seats and on engine side, the four cyl. engine mount brackets, and muffler shield. I built it for the street and track and really wasn't too concerned about the weight. Wasn't building it to race although it would pass tech. I knew that I wasn't just going on pleasure drives with it so I made it to do HD track duty. Just think about what you intend on doing with the car and build it that way.

The factory did not put much engineering effort into the GT stiffening kit.
It was a afterthought at best.

People had 35+ years to improve on the GT kit ...
Andy

I think it depends upon how bad your longs are.
I personally think the long overlay kit that Restoration Design made is easier and less work to install. (AA has them in stock)
If your interior is already gone, then fire away. the engman kit ties the floors in nicely, and ties the rear firewall in much better.

If your longs are ok and you intend on putting a complete cage in, I dont see a reason for either kit...the cage will transfer the load.

The GT stiffening kit is not required. Find the thread with pics by Jeroen and look at what he did...he opened up the shock tower and seam welded it...problem solved.

rich