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New here - Couple Questions
Posted: May 27th, 2009, 9:49 am
by manicjester3
I've got a couple tired 258s, and I wanted to make a stroker since I've got an extra and my truck, a 1979 J 10, could use a bit of power.
I found a guy with a 1998 4.0L for cheap but he only has the intake/exhaust manifolds, computer and wire harness from a 2001. I was wondering if the computer and harness from the 2001 would work with the 1998 motor since the 1999 and newer 4.0Ls had coil packs instead of a distributor.
Re: New here - Couple Questions
Posted: May 28th, 2009, 7:44 am
by 1bolt
This is a good question, I'm not sure myself. I would say this though, keep an eye on Ebay I've seen entire engine harness' go without bids for 19.99. so less than $50 bucks is very doable. Same goes for engines. I've gotten more free 258's and 4.0's but I've also seen good 100k mile 4.0 go for opening bids of $200 bucks.
I wouldn't hesitate to build ANY 4.0 ... Renix (swap on an HO head and manifolding though) HO or even the 99+ and later, I would have any 99+ head checked thoroughly for cracks but chances are at this point the 0331 heads that are out there are either cracked or they aren't going to... They've been through enough heat cycles at this point.
My Ideal engine build would be (assuming standard Jeep uses emphasis on torque):
good 258 donor
4.0 rods, custom/stroker pistons (shooting for zero deck, quench distance set by the thin head gasket)
96 or later 4.0 block (because you'll get a crank girdle with it and noise/harshness improvements to the block will mean a stiffer block)
RV cam
0331 cylinder head from Alabama cylinder heads (their heads are revised to fix early 0331 head cracking issue)
Modified dual outlet Borla long tube header or factory Iron 99+ manifold
Split exhaust (dual pipes that are separate all the way to the tailpipes, no H pipe or X pipe)
99+ intake manifold/PS pump
OBDII computer/harness (can put a Scangauge on it to really keep track of it). Or aftermarket EMS dyno tuned.
93 octane to allow high dynamic compression.
That recipe should have more low and mid torque than most strokers, by a significant amount... Long intake runners + long exhaust runners + low overlap cam