I respect your opinion Bill. I never claimed that the Opel 3.6 and Chevy 216 should be exactly the same engine as it's not, they are very similar as the pictures shows, but if you go into details you can of course find differences. The Opel 3.6 engine is obviously based on the Chevrolet 216 design as the article I provided says, but it's not an exact copy, the measurements are converted to the closest metric equivalent and it's developed and made by Opel to their own specs and for their own needs, it's not like they took raw engine block and head castings from Chevrolet and machined the internals to metric masurements, no the castings were made by different foundrys with their own molds half a World away so they are not 100% alike if you go into details. As I see it the differences between them are not like "apples and oranges", more like green appes and red apples...close outside apperance but tastes a bit different.
Here are a couple of pictures I found of the Opel 3.6 Litre engine.
And a couple of pictures of the Chevy 216 cui
I'm no expert on these engines but they looks to be quite similar to me. If an engine is based on another engine design doesn't mean they have to look exactly the same, they were built by two different manufacturers with their own foundrys and casting facilities on opposite sides of the Atlantic Ocean so of course there are differences here and there, but to me they look very close on the outside.
I don't think it would be that difficult to do a 1973-74 from the AMT W925 kit, just change the door handles on the AMT cab to the later slam lock ones from the Revell Snap kit and you are basically done. Remember that the KW "bug" grille emblem is gold on 1973 KW's, not the usual red, 1973 was Kenworth's 50th anniversary and all KW from that year had gold emblems...I have seen the Smokey And The Bandit movie a gazillion times since the first time I saw it at the movies in 1977-78, and I have studied it closely as I also plan to do the Snowman truck...and in most of the outside scenes (if not all) the Snowman KW had the gold grille emblem, the yellow "Tod Engels" KW W900 in the first scene in the movie also has this gold grille emblem.
Well I did some research on the Opel 3.6 litre inline 6 subject a while ago and found this regarding the Admiral/Blitz engines from 1937 to 45, and that's what I grounded my earler statement on. Nothing fits between them as it's all metric but it's still based on the Chevrolet 216 according to this article. In 1936, and I assume here that the American deputy chief engineer at Opel Russell S. Begg was responsible, a new engine was designed for the forthcoming Opel Admiral model. The engine for this large Chevrolet-sized car was based on the new 1937-on 216 cu. in./3,549 c.c. 6-cylinder Chevrolet engine, with four main bearings. The Opel engine was copied from the Chevrolet by redrawing the original blueprint drawings and converting from Imperial to Metric measurements. In fact, at the end of the day the engine more closely corresponded with the Canadian Pontiac car engine for 1937, the 224 cu. in. unit, which was fitted into a Chevrolet-based bodyshell to create the Pontiac 224 model and also in Canadian GMC trucks. The “224” unit was created by increasing the Chevrolet 216.5 unit bore by 0.0625”, with aluminium pistons instead of cast iron. The Bore & Stroke were then 3.5625 x 3.75 in. [3 9/16 x 3 ¾ in.] [30.2 H.P. rated engine measured exactly at 224.1 cu in. The Opel engine became 90 x 95 m.m. Bore & Stroke, the nearest Metric equivalent, or 3.5433 x 3.74015 “, for 3,626 c.c. [Rated at 30.1 H.P., producing 86 b.h.p. @ 3,200 r.p.m.]. The Opel car engine had a 6:1 compression ratio as against the Chevrolet 6.25:1, and used the same transmission ratios as the Chevrolet: 2.94:1, 1.68:1 and 1.0:1.The smaller 2.5 and 2.6 Opel engines are a different story.
Opel is owned by GM and the 6 cylinder 3.6 litre engine in the older Blitz trucks and Admiral's were a metric version of the old Chevy Stovebolt 6. The later 6 cylinder in the later Blitz and Kapitän was an Opel developed 2.5 litre engine.
As long as the engines are from the same family they look pretty much the same on the outside, so a Chevy small block based 383 stroker engine looks like a regular 350 and the things that may differ on the outside are intake manifolds, valve covers and air cleaner and if it has headers or original exhaust manifolds. Same goes for almost any other engine familys, so if you need a specific engine you can take almost any engine from the same family as the one you want and call it what you like as most of the differences are internal...and that's not visible. Here is a list of the American made engine familys I put together some years ago, it's not complete but covers most of the engines we use. Chevrolet V8: Generation I Small Block (1955-91) 265-283-302-327-350-400 cu in and most of the aftermarket "crate" or "stroker" engines based on the CSB. The 265 had the oil filter mounted on a bracket top of the engine and the early ones didn't have spin on oil filters, otherwise they basically look the same Generation II Small Block LT engines LT1-LT4-L99 The LT5 349cui 32 valve DOHC engine didn't have much in common with the other LT engines. Generation III Small Block LS engines LS1-LS6 and Generation IV L76-LS2-LS4-LS7-LS9 Big Block Generation 1 W-engine (1958-65) 348-409 and the Z-11 427 cu in, the 348 has oil dipstick on drivers side and 409 on passenger side, the 427 Z-11 had two part aluminum intake manifold. Big Block Generation 2 Rat engine (1965-) 396-402-427-454 and the "crate" 502-540-572 cu in, the larger displacement engines has taller deck The 427 ZL-1 engine was all aluminum but looks nearly the same as the cast iron big blocks
Buick V8: "Nailhead V8" Generation 1 (1953-1956) 264-322 cu in Nailhead Generation 2 (1957-66) 364-400-401-425 cu in, looks similar to the Generation 1 Small Block (1961-80) 300-340-350 cu in Big Block (1967-76) 400-430-455 cu in
Small Journal Engines (1955-62) 287-316-336-347-370-389-326-400-350-366-301-265 cu in Large Journal Engines (1963-?) 421-428-455 cu in Oldsmobile V8: Generation 1 Rocket (1949-64) 303-324-370-371-394 cu in The 371/394 series is a completely different casting for the block, heads, crank, cam, everything externally and internally. Although some minor parts might swap back and forth. Generation 2 Rocket (1964-90) 260-307-330-350-400-403-425-455, the larger displacement engines had taller deck.
Cadillac V8: (1949-62) 331-365-390 (1963-67) 390-429 redesigned, 1" lower, 4" narrower and 1 1/4" shorter than the 1949-62 engines (1968-) 472-500 and 368-425 Ford V8: Flat Head (1932-53) 136-221-239-255-337 cu in (1937-40) 136 cu in 60 hp, 17 stud heads, waterpump in block, center head water outlet . (1932-38) 221 cu in 65-75-85 hp, 21 stud heads, '32-'36 waterpumps in heads, '37-'38 waterpumps in block, front of head water outlet,"eggshell"/"drivers helmet" style distributor. (1939-48) 221-239 cu in 85-90-100 hp, 24 stud heads, waterpumps in block, center head water outlet, '38-41 "eggshell"/"drivers helmet" style distributor, '42-'45 "crab"/"pancake" style distributor, '46-'48 "round" style distributor. (1949-53) 239-255 cu in 100-110-112-125 hp, 24 bolt heads, waterpump in block, front of head water outlet, "round" style distributor. (1948-51) 337 cu in 145-152-154 hp, 27 stud or bolt heads, waterpump in block, front of head water outlet, rear mounted distributor, used in Lincoln cars and Ford Trucks. Y-Block (1954-64) 239-272-292-312 cu in Lincoln/Mercury Y-Block (1952-57) 317-341-368 FE Series (1958-76) Generation 1 332-352-360-361-390 cu in Generation 2 406-410-427-428 cu in 427 SOHC are basically a 427 FE series block with the special SOHC heads, valve covers, timing chain cover and intake manifold 427 Side Oiler has a cast in oil line on the bottom of block side on the drivers side and some had vertical ribs on the passenger side but otherwise looks basically the same as the other FE engines. MEL (1958-68) 383-410-430-462 Windsor (1962-95) 221-260-289-302 cu in and 5.0, the 351 Windsor looks basically the same but has 1.5 inch taller deck. BOSS 302 (1969-70) is basically a 302 Windsor block with 351 Cleveland style heads and different intake manifold 335 Series (1970-82) 351-400 Cleveland 385 Series (1968-97) 370-429-460 cu in BOSS 429 (1969-70) is a 385 series 429 block with Hemi heads and different valve covers and intake manifold. Ford Straight Six 1st Generation Flathead Six (1941-51) 226-254 2nd Generation OHV Six (1952-64) 215-223-262 3rd Generation Falcon Six (1961-77) 144-170-200-250 4th Generation Truck Six (1964-96) 240-300-4.9L
Mopar V8: Chrysler Fire Power Hemi (1951-?) 331-354-392, the 392 had taller deck Dodge Red Ram, Super Red Ram and D500 Hemi (1953-?) 241-270-315-325 De Soto Fire Dome and Fire Flite Hemi (1952-?) 276-291-330-441-345 The older Chrysler, Dodge and De Soto Hemis looks very similar but there are differences both internally and externally. A Series "Wide Block" Polysferic Head (1956-67) 277-301-303-313-318-326 cu in LA Series (1964-) Small Block 273-318-340-360 cu in B Series Big Block (1958-78) 350-361-383-400 cu in and RB Series Big Block (1959-78) 383-413-426-440 cu in and 413-426 Max Wedge (1962-66?), the RB Series had slightly taller deck than the B Series (1964-71) 426 Hemi and "crate" 528-540-572 Hemi, the 426 Hemi is based on the RB series block design.
AMC/Rambler V8: Generation 1 Nash/Hudson/Rambler (1956-66) 250-287-327 cu in Generation 2 AMC Short Deck (1966-70) 290-343-390 cu in Generation 3 AMC Tall Deck (1971-91) 304-360-390-401 cu in The Generation 3 engines looks similar to the Generation 2 but had taller deck and slightly different head design.
The Edsel Corsair and Citation are Mercury based and are quite far from the smaller Ford based Ranger and Pacer and I don't know if any 57-8-9 Mercury has been made as a model, so the Laurie Edsel are a bit hard to do..but if you want it enough it can most likely be done. The Milner 32 Ford has been made by Revell as an pre painted unassembled diecast kit, and MPC did a quite wrong plastic kit reissued by AMT a few years ago, MPC also did the Milner dragster from More American Graffiti, not a good one as with the 32 coupe but they did one anyway. The Falfa 55 Chevy was also made by Revell as a diecast kit and you can for sure convert the AMT 55 Sedan to resemble the movie car, or take a Revell 55 and graft on the roof from their 56 Del Ray to do a 2 door post. The Steve/Toad 58 Impala isn't that hard to do from either the AMT kit or the Revell kit. The Pharao's 51 Mercury, a 51 Mercury hasn't been done as a model kit and the 51 differs quite a bit from the available 49 Mercury's, the rear quarters are longer and the rear window opening is wider and has a different shape than the 49-50, the dash board are also different in the 50-51 so the 49 dash is wrong. The 56 Thunderbird driven by Susanne Sommers has been done by AMT as mentioned and Revell also did a pre painted diecast kit of the car. The Curt Henderson Citroën 2CV can most likely be done as Revell, Heller and Tamiya has done 2CV's, I don't know if they are the right year but there are not that much that differs. Holstein's 61 Galaxie Police car can maybe be done from the old AMT Styline kit