Wow! thanks for all the feed back. i'll adress you individualy...
5-90, it's not that i don't like dealing in persise measurments i just haven't had the opportunity and i'm anxious to learn! It's kinda hard trying to teach yourself about such complex things. I will take your advice on the model head to use. And thanks for clearing up the crank confusion. Just to make sure, the late model crank would need no modifacation for use in my stroker? I'll look into those throttle bodies you mentioned. Which models of ford should i look for? (i'm lucky and have 3 highly stocked JYs within 15min) As far as the wiring harness goes, in the latest issue of JP there was a thing about a company selling full wiring harnesses for 4.0 swaps should i look into this as a possible option? And thank you again for all the info and stuff you've given me a lot to chew on.
Given that I'm writing what (I hope...) will be
the references for Jeep buildups, I probably have plenty to help you with!
Throttle bodies? Ford Pax 302ci V8 or 281ci V8 - Mustangs, Crown Vics, and like that. Merc/Lincoln with similar engines.
The late model crank should drop right in without having to cut the snout or install a spacer. It is, however, the "light weight" crank (either four or six counterweights, I don't recall offhand) and would work better if you're putting an automatic behind it. If you're going to use a stick, you're probably better off either getting the early "12-cw" crank (twelve counterweights, and about fifteen extra pounds rotating weight,) or/and having your flywheel machined for an "inertia ring" - which is a "heavy metal" band put into the backside of the flywheel, near the permeter (I think it's the same alloy used to weight a crankshaft for balancing, "Mallory Metal," as I recall.) This will help you when getting started from a standstill, but could negate the "crisp" part-throttle response you'd get from the bored tbody (up to a certain point, they'd balance each other out. No, I don't know what that point is offhand.) The earlier crank can be installed unmodified - you'll just need to have a 10m/m "slice" taken off of the rear end of your old harmonic damper. It all goes together in the order: harmonic damper-spacer-thick washer-screw, and that will properly locate and retain your harmonic damper.
First things first - find yourself a Factory Service Manual (even my books don't take the place of an FSM - I saw no need to reinvent the wheel, and it's easier to ship a 200-page book than a 700-page book, not to mention printing, binding, ... I'm still very much a "one-man band," and I do all the work myself.) RENIX is a bit old, so try eBay. Alternatively, you could hit me backchannel (PM or e-mail off-list) and I'll check the Archives for you.
WRT cooling - I've yet to see any trouble with the RENIX cooling system - and I've owned
five RENIX rigs to date. The only one that ran a little hot was the one that I bought already converted, and I was seriously considering converting it back. If the "closed" system is so flawed, why are OEMs going to it? My wife's 2005 Verona runs a closed system, and not a lick of trouble out of it.
The biggest problem with the RENIX cooling system is that the OEM radiators (per Jeep techs) tend to start to scale up around 150-180K miles +/- - and even the dealership up the street would install aftermarket Modine radiators (same brand I prefer, as it happens) to replace them. Problem solved. Flush it every two years and change the coolant, and it's a non-issue.
The "volume" bottles - with caps! - should still be available from Morris 4x4 Center (they're a sponsor, so look here for the link) for a reasonable fee. I find that 7-10 years seems to be about the average service life for the thing - so replace yours and order a spare. Write the date you install it on the new one.
The fan clutches are typically good for 4-5 years (regardless of model year - the XJ is just rough on them,) but they're readily available and write the date on them as well. I tend to use Hayden heavy-duty units, Flex-A-Lite, or similar (Hayden and Flex-A-Lite are easiest for me to get my hands on, and cost about half of OEM. I don't use much in the way of OEM parts...)
The plastic heater control valve (near the firewall) can be safely eliminated entirely - which removes a potential point of failure. If you're handy with a propane torch and silver solder, you can replace most of the heater hoses with copper lines (use 1/2" ID - it's right about 5/8" OD, and will fit neatly in 5/8" hose) and cut the cost of renewing that considerably. Moulded right-angle hoses are expensive, copper tube isn't really. NB: there are two spots where you'll need to go into a 3/4" hose, upsize the OD of the copper tube with a straight union. See here:
(Yes, it's a big pic. Yes, it's also mine. Nyar!)
Please don't ask me for measurements - I lost my notes, and need to refine the setup anyhow. However, it's a simple mod - that took me about a half-hour to stomp up.
The problem that most people have with the "closed" system is simple - you tend to get an air pocket behind the thermostat. The fix for that is also simple - drill two 1/16"-1/8" holes in the thermostat flange, 180* apart. Install with one hole at 12:00 and the other at 6:00. The system should then purge itself. (If you want to make sure you get the engine block filled up afterwards, disconnect the upper hose at the engine and slowly pour coolant into the thermostat housing. Let it trickle in. It's a bit slow, but it's easier than jacking up the rear and removing the temperature sensor, and it also gets it filled up a bit better. With less work. And - usually - less time.)
Wiring - I'm almost willing to bet that you're looking at an advert for Painless Performance. Their stuff is top-notch - and you pay for it. I've used several of their kits in the past with
excellent results.
However, their kits are probably OBD-I/OBD-II, and I doubt they'd work with RENIX controls. No harm in askin', tho (I don't typically read the adverts in detail, I usually just scan over them looking for anything really different.)
Anything else? :lecture:
! 
