T1 jug length/std deck

[Piledriver]

Looks like I am building a T1 motor for the first time in ~30 years, have a couple questions.

Deck: The apparently OG (std/std/std AS41 blocked #211 VW stock cam/oil pump and perfect VW bearings) core had Mexican P&L in it, with all as found the pistons were ~.100" down the hole at TDC, plus the heads had a deep step cut built in, making for a >.200 deck height, which is ridiculous and will result in an untuneable motor IME.

I ask because the aftermarket T4 jugs from AA are typically .120 longer than stock, which is a feature if you A)know about it and b)building a stroker.

If I buy Mahle stock 1600 P&L what deck is to be expected? (What's normal range?)
Considering buying longer rods to fix it properly.

Will be having block massaged and may do something more interesting with it...
Unfortuntely the heads appear to have just been rebuilt, so I'll have a hard time justifying a pair of better heads.

[Marc]

I'm not familiar with Mexican P&L but German and Brazilian (and to the best of my knowledge AA Chinese as well) should all yield a nominal piston deck height of around .055" if used without the stock paper gasket (~.008" thick) on a virgin case. You should not have to resort to 5.5" rods for a "stock" build, especially if the case is going to be decked. Since rods get shorter every time they're rebuilt/resized, it's possible that your excess piston deck is due to rods that have been around the block too many times. Stock center-to-center length is 5.394".
Many late DP heads had a step in the chamber, not .100" but at least .055", which yielded a C.R. of around 7.3-7.4:1 with flattop pistons at nominal deck height. The purpose was to prevent detonation in order to lower peak cylinder temps and NOX emissions. Whether you want to believe it or not, a tight deck is not really needed when there's enough intake velocity to ensure turbulence - with stock ports and mild cam timing, it's just not as big a deal as some folks make of it. Type I heads do not have cavernous, lazy intake ports like Type IVs. Some rebuilders, in particular those based in hotter climes, will routinely whack a step into a "normal" head just to drop the C.R. too far in order to reduced their odds of warranty work (customers who would bitch over hot-running or premature death are more likely to accept low power and crappy gas mileage) so if yours are truly .100" that's probably how they got there.
You're probably going to have the step flycut out, but if you leave it and opt for poking the pistons out further be aware that if it's a factory feature its I.D. is slightly tapered and not quite big enough to afford safe clearance to an 85.5mm piston so you'll want to maintain ~.045" piston deck or more unless you have the step's I.D. opened up a tad. In any case, don't go under .045" piston-to-head.
Don't forget that if, once you've settled on the chamber CCs and other parameters, there are stock pistons available with a small dish in the center which can be used if needed to tame the static C.R. without disrupting your beloved quench. P/N 211 198 069
With a stock cam/pump gas (even Premium) I would never advise exceeding 7.75:1 on a Type I. ≤7.64:1 should be your target unless you're going to be putting in a bigger bump-stick.

[Piledriver]

Just a follow up:
My one remaining neuron fired when I was using my calipers measuring the sway bar on my TDi for new bushings

The "MORESA" pistons in the 1600 had a pin height of 38.6mm, which IIRC is supposed to be 39.6 or thereabouts, thus going a long way to explain the >.200" deck height..

It's possible someone took some off the top, the crowns appear to have seen a lathe.

I'm still trying to decide if I want to deal with a ~stock build, build a 2L t1 wth a wbx crank (that I don't actually have a car for any T1 ATM) or just pass along an uncut block rebuildable core.

[Marc]

Have you seen the "thickwall" 88mm Type I P&Ls from AA? They have the stock 90mm lower register so no case machinework is needed, but ample wall thickness where it counts because they take the same 98mm head cut as 92s.
If I was building a near-stocker that needed new jugs I'd use those in a heartbeat - 1679cc with minimal expense and without the liabilities of the "slip-ins".
A 2 liter (actually anything over about 1850cc) is going to need a bigger exhaust system - if you want heat the stock boxes won't cut it, and it'll be choked by 35.5x32 heads even if they're ported.
The 1679 with stock-valve heads is going to lose some RPM potential compared to a 1585, but not enough to be missed (actually desirable with a non-CW crank) - select a mild cam to make the most of the 3000-4500 range where 95% of normal driving occurs. DO 8-dowel the crank/flywheel though - a healthy 1679 makes too much torque to trust to the stock 4 dowels.