L26 swap questions
 

Hello everybody! I'm new to the Monte mod stuff, and I had a couple questions...

1) My monte has some miles on it (180k), and pondering a minor upgrade buildup/rebuild...does the L26 long block swap 1 for 1 with a L36? Does the short block at least?

2) all the L36 to a L26 intake swaps/threads I've seen all use an L67 throttle body. Can the original L36 throttle body be used? I picked up a L26 uim for cheap and was looking at doing the uim swap.

3) I'm not fond of plastic uims... Is the dorman plastic uim the best? Or zzp? Or ???

I used a L36 tb with my l26 plenum, just need an adapter from zzp that's all. And I believe everything from the lower intake down is the same between l26/l36. The differences in them are upper plenum, tb, fuel rails.

How much was your adapter if you remember?

I do not remember exactly. Its been like 5yrs now since i did this but guessing I will say around 80-100 possibly?? I also used l36 fuel rails over a L26 plenum. It's close but it works.

The L36 and L26 are near identical and for the most part, straight up swap. The primary difference is the aluminum UIM and returnless fuel rail on the L26 (lower intake and everything else, all the same). I believe in 2005, the L26 received forged connecting rods instead of cast. I have read that there are possibly some issues that make a L36 more desirable over a L26 (I don't recall what those issues are).

Primary reasons people use the L67 throttle body is that the mating surface/exit of the L67 throttle body better match the L26 UIM and the L67 throttle body is bigger allowing more air in. The L36 throttle body as Turbo mentioned works just fine.

I swapped a L26 UIM on my Monte. It's not 100% a straight up swap. At minimum you need to determine how you are plumbing the PCV and the vac line that originally connects to the throttle body (as the throttle body is now a few inches forward).

I did a L26 UIM swap and posted all my information about it here:
https://montecarloforum.com/forum/fw...c-heavy-48949/

Question - any reason you'd be looking to swap in an l26 instead of another l36? As mentioned above, they're virtually identical, and there are a ton more l36s out there in junkyards. Also, when talking about doing upgrades, keep in mind that the l26 is the weakest of the s2/s3 3800s (something I'd only worry about if you plan to boost it and push it).

As for intakes, I did run a Dorman intake on my 3800 impala for about 75k miles. It was definitely beefed up more in the EGR area. Plastic intakes in general really aren't that bad- look at the LS intakes for example. It's all in being designed properly from the start. IMO the hard part for the 3800 is that it runs exhaust gas back through it.

I recall reading some fault with the L26 that goes in hand with your statement about it being weaker then the L36. For the life of me, I cannot recall what it was. Do you remember off hand?

Nailed it. The plastic intake is also lighter then the aluminum.

Admittedly, I swapped mine to the L26 for looks more then function. Since I plugged off the coolant ports on the LIM connecting to the UIM and installed a narrow EGR stove pipe, I reduced issues with my UIM ever failing and causing me a problem.

In reguards to swapping in an L26, I was thinking the l26 would be stronger because of the upgraded rods, and I was thinking I would have good odds of finding one with low miles. Mine has 180k, it's running pretty well right now, but I'm concerned it'll be downhill from here and to be honest I think it's a little down on the horsepower... So I was thinking of scooping up another long block, sending off for some zzp ported heads, rocker arms, zzp plog header and u-bend eliminator downpipe and some arp studs for the heads, and I happened to get a L26 uim for cheap...

The new motor would be built with boost in mind, and possibly boosted later. My current motor uim is plastic and unknown miles and for all I know is original. I'm thinking of installing the aluminum uim on my current motor and maybe swap it onto the new motor if I can't come across a good price on an L67... Or I might just do a turbo L36 setup eventually if I can't find a good L67.

From what i am told the l26 rods and l32 rods are a "forged" powder metal= junk. Use a L36 or l67 bottom end for sure