I didn't find this in my searches, and I have personally asked a very generic which one is better and got a "they are both good in the own right". Though, I am curious about a few things.

Which setup would yield faster 1/4 and 0-60? A fully tuned turbo 3.4 DOHC, or a tuned SC L67?
I know the DOHC has a mean power band. Also the L67 has some serious torque. I just haven't seen anyone put a turbo DOHC against a SC L67 yet. The SC L67 eats the DOHC hands down, but I would question both racing naturally aspirated. I figure if they are both "blown" (correct me if thats not the right term), it would even things up a bit.

Would it be worth it to de-supercharge a L67 and turbo charge it?
I prefer turbo's and I figure its already got the strong bottom end.

Well they both have some advantages,

The 3.4 DOHC is easier and cheaper to build and rebuild, can rev like crazy, and have aluminum heads, plus they use the same motor mounts and is a direct bolt up, but there is a very little market for aftermarket cams and the "60degreeV6" engines have a tendency to randomly break with little warning.

The 3800 is a solid motor that will run forever (in stock form), I've personaly seen 350K on the odo, they are built to hold well over 400hp and have great documentation, but they are very expensive to rebuild, $1500+, and can easily chip a piston if spark knock is present.

I'm not sure if you are planning on turboing both of them or it your leaving the l67 super?

The 3800 would be your best bet if you are going to stay out of the bottom end and just add power.

A built up 3.4 would probably be a faster car, and cheaper to buy and upgrade. Plus it sounds more exotic.

Its up to you i'd go to pull-a-part or Pick-a-part etc. and find the best motor you can find and go with it.

After owning a DOHC I would not do the same. The 4.9 sounds like a better idea to me.

Both of the two engines are great. The 3.4 sounds good and has a high red line. The 3800SC is a monster but does not sound that good unless you get the small pully and drown out the crappy V6 sound with SC wine.

quote Originally posted by Rickady88GT: The 3800SC is a monster but does not sound that good unless you get the small pully and drown out the crappy V6 sound with SC wine.

That would be a matter of taste or what sound you're looking for but, we've all got opinions. Mine is no better than yours.

Ron

There have only been a handful of the 3.4TDC turbos done and at least 3 of them run getrags and one was running the 4T80. With these few examples, it is difficult for the vast majority of us to make an credible comparison between the two.

They both can be made to perform from a peak HP perspective and if you look at the 1/4 mile thread, they both have pushed fieros into the 11's with the getrag.

I think the ECM requires a little more work for a boosted 3.4TDC (2 of the getrag cars run a Haltec aftermarket ecm) vs. the 3800 which came in boosted form.

I would say a lot depends on the car, personally I prefer the 3800SC for its reliability, power and ease to work on in the car.
Now if I was to be building a kit car like a Ferrari or Lambo then I would most likely go with the 3.4 DOHC for its high revving abilities making it sound more like a real Ferrari or Lambo, plus with a stretched frame there is more room to fit the 3.4 DOHC and more room to work on it once it is installed. Dan