LocostUSA.com

http://www.carnut.com/specs/engdim.html Found this handy engine size reference. The dimensions include the stock valve covers I noticed.

Thanks Downix. I'm surprised about some of the numbers there. I think we're going to need some pictures with rulers. I'm just guessing like with engine weights there are a lot of variables.

Oil pans, intakes, exhausts and maybe valve covers must vary a lot. I'd like dimensions based off the crank centerline or block/heads and then we can discuss things you do to shrink all that extra stuff. In our general case I would argue that horsepower is not really the issue. Any V8 will produce "enough" without extra effort. For people that want more, that's fine, but let's try to accomplish the easier things first.

No doubt. The dimensions are a major step but they vary so greatly it is crazy. Unfortunately (though at the time I was fortunate, I guess), I never had to worry with the dimensions. And I don't have a 302 sitting around to measure (now THAt is unfortunate! ). Does anyone have concise dimensions of the 5.4L also?

When it comes to IRS for the 5.4L would anyone have any knowledge about what I could use? I have thought about the rear end from a GTO (the '04-'06) or even the IRS from a Mustang Cobra (which are a little more expensive from what I can tell). IIRC, JD, you used the IRC from the Cobra. I am pretty sure that either IRS could handle both the 302ci or the 5.4L (aka the 330ci).

Does anyone have an opinion on either?

Any input is appreciated!



-Sam

Yo, Sam-
Actually, I used a mish-mosh... The uprights/brakes came from a T-Bird/Cougar, as did the axle shafts. I bought "kit car" hubs to convert to 5 on 4.5 bolt pattern, built my own control arms, and I've got the diff out of a Mustang Cobra. (probably the source of your memory) Rumor has it that the geometry of the Mustang Cobra IRS is not the best, having been compromised by packaging concessions to make it bolt up to the standard Mustang mounting points.

The IRS diff out of the Explorer has a more robust looking mount than the Cobra one. A buddy of mine sold me the Cobra diff for next-to-nothing, couldn't turn it down. Next time, however, it might be an Explorer unit.


JDK

That's right. My memory is so terrible. I haven't seen anyone here use the Explorer IRS. Does anyone have any experience with it?



-Sam

I think Moti used a diff from an Explorer. He has a build log here with some pictures. Maybe I'm wrong, I'm afraid if I learn one more new thing here, I'll start to forget my kids names... It is that family of parts though...

If you like the Explorer mounting setup, you could also try the Explorer rear cover on a Cobra (or Mk. VIII + Torsen) center section. I believe that the Explorer unit uses a few unique (non-interchangable) parts (axle bearings and seals maybe?) compared to all the other 8.8 IRS units more commonly used in performance applications. Obviously this isn't necessarily a problem for completely custom 1-off cars like these, but might still be a consideration for some people.

I used the entire Explorer differential . It had 3.73 gears and a posi. It uses 31 spline axles(t bird are 28) which have different seals than the 31 spline cobra axles. I used 2 axles from the same side of an explorer( pass side if i remember correctly). The splines on the outside of the axles also do not mate with the T-bird or cobra hubs( too large). I had a set of explorer hubs machined down to match the shape of the cobra /tbird hubs. The OD of the wheel mating surface had to be brought down to fit inside the brake rotor and the OD of the bearing surface had to be brought down to press into the t- bird spindles. Alot of work to get it done , might be easier to grab a posi from a supercoupe rear and just buy the gears you want.

Phil