Ok so I have a 67 302 out of a Z28 camaro can I use a 305 crank in it

 

No.

Main bearing journals are the wrong diameter.

That's about the dumbest idea I think I've heard all day, in a day full of really dumb ideas coming at me non-stop from all sides. Sell that block to somebody with a 67 Z28... you can buy about 500 305 cranks with what a 67 302 is worth. Maybe 1000. You can probably buy all the 305 cranks in all the junkyards in the US with the price of that block, for that matter.

 

To do what? Keep it a 302 or make a 305 out of it?
The 302 has a 3.000" stroke and pistons with a compression height of 1.800 inches.
The 305 has a 3.480" stroke and pistons with a compression height of 1.560 inches.
Both engines used 5.700" long connecting rods.
The 67 302 used the small journal crank (2.300" mains & 2.000" rods).
The 305 has large journals (2.450" mains & 2.100" rods).
The 305 crank will not physically fit in your 302 block because the main journal diameters are too large.
If you somehow managed to put the 305 crank into the 302 block (keeping the 302's rods and pistons), the pistons would then stick .480" out of the block at TDC.

NO, you can't do this.

 

The 302 used a 283 crank. Back in the day, we used to call putting a 283 crank (3.000" stroke) into a 327 block (4.000" bore) a 301. It's really 301.59", so, yeah.

283 was 3.000" x 3.875". 327 was 3.25" x 4.000". 307 was 3.25" x 3.875". 301/302 was 3.000" x 4.000". Notice a pattern anywhere?

The factory did that so they could run in the SCCA Trans Am series, which at the time, had a 5.0L hard limit on displacement (5.001L would not have been allowed for example), and also, there had to be 500 "homologues", which are cars IDENTICAL to the race version ACTUALLY SOLD at dealerships as customer purchases, complete with warranty etc. Interestingly enough, Pontiac, the master of "performance car" marketing within GM who had LONG SINCE figured out how to capture the IMAGE of "performance" with NOT A TRACE of the "performance" of "performance", paid the SCCA for the use of the name, rather handsomely I might add, even though they didn't bother to run a car in the series. (as the old adage goes, an ounce of image is worth more than a ton of performance... goes hand in hand with the drivel about how perception is reality, and is spouted by the same kind of liar) It was quite a few years before SCCA's rules changed enough that Pontiac could participate.

FYI, Pontiac got their eye on the idea (*cough*johndelorean*cough*) acoupla years earlier; GTO is the TLA for Gran Turismo Omoligatto, which would be the Italian for "grand tourism homologated" if any such thing had ever existed. Butt of course the GTO never ran in any kind of racing series where homologues were required; that was beside the point, as far as Pontiac (*cough*johndelorean*cough*) was concerned. All that was wanted was the IMAGE, not necessarily the ability, to PERFORM, or recognition of any such by any "peers", or any record of it.

I'm not the betting kind, but I'm almost (not quite) willing to bet that you don't have a 67 302 block. If I WAS the betting kind I'd bet you have a 327 block, maybe from 67 or maybe not. Given that there were only acoupla thousand 67 302s and anybody that has one wouldn't be (a) stupid enough to put it in a 81 El Camino (LEARN HOW TO READ THE LABEL ON YOUR CAR) and also wouldn't be (b) stupid enough to even consider an idea like that, and (c) wouldn't come into a site EXCLUSIVELY DEVOTED to 3rd generation (82-92) Camaro/Firebird with abuncha monkey-spank and bishop-buffing like THAT to make your first post about.

 

Incidentally, to add to some of the SBC dimensions:

The small-journal motors were the 265, 283, 302, and 327. I listed the dimensions of the others; the 265, the original SBC, had 3.750" bore and 3.00" stroke, so it, the 283, and the 302, all had the same stroke, and were 3.750", 3.875", and 4.000" bore. Could there be a pattern here?

Starting with the introduction of the large-journal SBC in the form of the 67 350, LJ motors were made in 262.5, 267, 302, 305, 307, 327, 350, and 400 CID.

The bore of the 302, 327, and 350 are all 4.000"; the strokes are 3.00", 3.25", and 3.48". Notice a pattern? (almost)

The stroke of the 267, 305, and 350 are all 3.48"; the bores are 3.500", 3.736", and 4.000". Again, a pattern. Almost.

The 262.5 was a kind of stepchild... 3.67" bore, 3.10" stroke. The 307 was another of a bit of a stepchild; 327 stroke, 283 bore. Both of these were shunned as "performance" motors, for the same reason the 305 is. The 307 was used in applications much like the 305 was at the start of its run: low-perf, heavy vehicles, with 2-bbl carbs.

The 400 was yet another oddball... 4.125" bore, 3.75" stroke. Very similar cylinder dimensions to the big block 402 (which in turn was the same dimensions as a .030" over 396). Used to be a popular magazine article topic to try to make direct comparisons of the 2 motors; they don't really compare very well though, for any number of reasons, not least being the difficulty of coming up with "equivalent" cams since the characteristics of the heads make it unrealistic to optimize either one using a cam that optimizes the other. Also it's quite difficult to make the compression "equivalent" because the chamber shape is so different, for any big-block heads later than 68 or so (the early ones were "bathtub" like early SB ones). It also used a different main journal diameter from the LJ motors. And, different length rods: the length of ALL other SBC rods is 5.700", but it's 5.565" for the 400.

As NoE posted, the journal diameters preclude simply jammng a LJ crank into a SJ block, or vice-versa; or, putting a LJ crank into a 400 block, or vice-versa. However, it is (or was at one time anyway) possible to buy "bearing spacers" to allow this; and some people would do it by simply align-boring a set of the larger bearings to the ID required to install bearings for a smaller crank journal dia inside them. Kinda, home-made spacers. You could do the same thing to put a LJ crank into a 400 block. To go the other way, you'd have to turn down the crank to whatever smaller journal size you wanted. I don't recall that being "a thing" to put LJ cranks into SJ motors, since there was no advantage to that, compared to just using a 350 block, not even in sanctioned racing where an older block was required, and the purpose was simply to CHEAT. Also, cranks are surface-hardened, to a relatively shallow depth, meaning that if you turn one down that far, you have to get it re-heat-treated so that the bearing surfaces are hard enough to last, which is NOT CHEAP. However, that was how the 383 was originally built, using all-stock parts; you'd take a 400 crank and turn the mains down to LJ size, then use stock 400 rods and stock 350 pistons, then of course you had a balancing mess to work through; but it worked. Later, aftermarket 383 pistons started being made that allowed the use of 5.7" rods, and up to 6.0" ones if you want for that matter. A .030" over 400 block with a 350 crank gives a 377; I built one of those once for somebody. He insisted. Then came back and said he wished he'd let me talk him out of it and build a 400, but it was too late of course.

Going back to the OP's claim of having a 67 302 block, there were just over 1000 67 Z28s made, and that was THE ONLY application that got that size motor, meaning, that there were ONLY 1000ish 67 302 blocks ever made. If he ACTUALLY has one of those, with THE RIGHT stamping code etc. FROM THE FACTORY (not just some machine shop decking a 67 327 block and re-stamping the code themselves), then his block is one of the last 5 or so left "in the wild" and not in a resto or clone 67 Z28 or already used up and scrapped, and is probably worth near as much as the house he lives in. Which is why I'm HIGHLY SKEPTICAL of his claim, although of course, it's certainly POSSIBLE he has what he said he has even if not too LIKELY. Certainly not likely to be lurking in some 81 Elky POS. For somebody to come in here and make a claim like that in their 1st post SMACKS of troll and liar though, trying to impress the forum with some big wow factor. Instead I think he just made a fool of himself but of course I could be wrong.

67 & 68 302s were SJ, 69 302 was LJ. The 69 302 crank was THE ONLY 3.00" stroke LJ crank from the factory: there are very few of those left in the world now as well. Although there were QUITE A FEW more 69 Z28s than there were 67s, it's still a pretty small universe to start out from, in the grand scheme of things. I've never laid eyes on one myself outside of a motor that I know of.

 

I imagine GM would have made some number of replacement parts and complete engines or short blocks for warranty and repair purposes. Available through the parts department at least into the 70's right? Of course at that time I'm sure the parts being replaced were thrown away. But some may have been sold for performance purposes as engine swaps or upgrades to lesser equipped models? Things like that happen a lot in the performance industry even today. I buy short blocks or bare blocks from the dealer to upgrade or build for customers because it's cheaper than doing machine work on the old one, or we want a higher performance unit.

GD

 

Not sure why we’re ragging on Pontiac, as a division within GM they could only ever do what they were allowed to do by GM corporate, which wasn’t much. Jim Wanger’s and John DeLorean came out with the GTO at a time when GM had a corporate mandate in place regarding maximum engine size in an intermediate chassis. Pontiac circumvented that “rule” by making the GTO an option on the base LeMans and the GTO and arguably the Muscle Car craze was born. GM management was royally pissed off at Pontiac, but the sales figures were good and $$$ mattered then as they do now. The other divisions quickly got on the bandwagon with the Chevelle SS, the Olds 442, the Buick GSX, etc.

Pontiac did develop a 5L V8 for SCCA Trans-Am racing but it didn’t get too far due to a lack of funding for development; again, GM corporate ultimately holds the purse strings. Chevrolet was the only GM division to receive full GM corporate backing to participate in this race alongside other rival domestic participants such as Ford (Mustang) and AMC (Javelin). Interestingly, Pontiac on their own did put together a Tempest that was competitive in this race but did not qualify due to homologation rules and it being a 6-year-old car at that time - it was allowed to start in last place and eventually ended up in second place behind a Javelin before its engine quit.

Pontiac always wanted a two-seat sports car of it’s own but the concept was always shot down by GM corporate for fear of direct competition with the Corvette. Pontiac had to raid the parts bins in the ‘80’s to get the Fiero into production, but there were a lot of compromises made due to a lack of GM support/funding which ultimately led to its demise.

Bottom line, GM has always pampered, babied and deferred to it’s “bread-and-butter” division and the other divisions have been historically neglected and left to fend for themselves with afterthought models, badge-engineering and marketing.

Pontiac’s gone now, RIP.

 

"We" aren't "ragging on Pontiac"; I am ragging on BASELESS MARKETING. I don't care who does it or what the motivation is. I don't care if it's the President of the United States, the Chairman of the Chinese Communist Party, the President of Venezuela, the [whatever it is] of Russia, doesn't matter. (notice a theme here?) I don't like it and I won't make excuses for it.

I don't have any kind of warm-&-fuzzies over Pontiac, to be sure; a look at that division's history will tell you why. Or for that matter, Chevrolet, although I find Chevrolet less offensive. I particularly don't have warm-&-fuzzies over Pontiac inventing some kind of "racing" heritage it doesn't have. Great muscle cars not withstanding. Muscle cars, yes; racers, not so much. And least of all, over the Firebird, which to me has always just been a Camaro with some extra tacky plastic bloat hung onto it, and I've always been annoyed since the late 60s by people who owned them arguing about "rare" and "valuable" and this option "triggering" that one and "only xx like this one produced" and all the rest of that. It's insulting.

Considering that Louis Chevrolet was a race car driver, who drove Buicks; so when Buick's former CEO Durant (the powerhouse behind GM in its early days: GM was built around Buick by the people that ran Buick, not the other way around) wanted to produce a race-car-like model after GM turfed him, and name it after A RACER, they had a go-to. Turned out though, a small light peppy car was a hit with buyers, as much as land yachts were. A chicken in every pot, a GM product for every market niche. As American as apple pie. And equally American, Durant used Chevrolet's success to regain control of GM.

Pontiac, a town in Michigan in the Detroit metro area, named in turn after a historical figure, was a last-gasp effort by the Oakland division (Oakland is another Michigan town, now also more or less part of Detroit metro) to avoid getting shut down in the mid 20s due to declining sales and poor financial performance (sound familiar?) since pretty much all it did at the time was put their own motor into a Chevrolet chassis and re-label it. To stave off the corporate axe, Oakland introduced the Pontiac model, and it became so much more popular than all the other Oakland products put together, that GM renamed the division and abolished all the other Oakland models.

The Camaro was created to compete with the Mustang. That car was of course the brainchild of a disgruntled former GM employee, John Delorean, the inventor of the GTO idea, who had a grudge against GM for not letting him do the next thing he wanted to do (big mistake on GM's part in hindsight) and jumped to GM'S main competitor for the chance to do it there instead. Mustang's marketplace success (the 65 Mustang became the highest-selling single car model in history, surpassing the 57 Chevrolet) shocked GM and caught it flat-footed, so they rushed a competitor for it to market by borrowing the Chevy II Nova chassis and slapping a sleeker-looking body on it. They were looking for a way to make it stand out as a racer, so they took their existing 283 and 327, and created a hybrid of them that passed the SCCA rules, perhaps by noticing that hot-rodders had already been doing that occasionally (although an otherwise identical 327 would outrun it). There really wasn't much "development" to it at all; not like they had to spend big $$$ to make that happen. Pontiac OTOH had no such thing available. According to insiders at the time, the successors to John Delorean, the man responsible for the GTO and later the Mustang, were SO PISSED that they didn't have something to compete with Delorean's new baby, that they INSISTED on getting access to the Camaro chassis, and ... re-labelling it & putting their own motor into it. History may not repeat itself exactly, but it often tends to rhyme. Then of course they took their "precious" "unavailable" GM corporate marketing dollars and BOUGHT the name of the series the Camaro raced in, to attach themselves to the IMAGE of racing even though they didn't have access to the SUBSTANCE.

It's all too eeeeezy to blame "GM corporate" and "compete with the Corvette" and all the rest of those EXCUSES for that division's failure. While no doubt it's true to some extent, the lack of innovative thinking and a genuine market position containing SUBSTANCE as opposed to PURE UNFOUNDED IMAGE (essentially, lies) were at least as much to blame.

 

To claim that Pontiac has no racing history whatsoever is dumb.

With regards to the development of Chevrolet’s “innovative” 265 V8 design in 1955, this is from Wikipedia:

”(Ed) Cole's design borrowed the valve train design scheduled to be used at the time in the Pontiac V8. Internal GM rules at that time were that once an automotive division had introduced a technological innovation no other GM division could use it for a period of two years. The stud mounted independent ball rocker arm design patented by Pontiac engineer Clayton Leach was scheduled for introduction in the Pontiac 1955 V8. GM forced the Pontiac division to share its valvetraindesign in Chevrolet's new 265 V8 in 1955, so that in the end both engines were introduced the same year with the same valve train design.[5] A side note to Pontiac's V-8 was the engine was supposed to be introduced on 1953 cars, and all 53 & 54 Pontiac's chassis and suspension were designed for the engine that didn't make it into a Pontiac until late 1954. The reason this happened is that Buick division lobbied the corporation to hold back Pontiac's release because it affected Buick's release of the new Buick V-8.”

The Chevrolet division has always been coddled by GM and GM corporate always had a love it/hate it relationship with Pontiac - they loved the dollars that Pontiac brought in when other divisions were struggling, but let them wither on the vine in favor of other GM divisions when it came right down to it. Pontiac tried many times to buck GM corporate with the GTO, the Super Duties, the Fiero, the TTA, each time raising the ire of GM corporate and each time without official GM corporate sanctioning, e.g. under the table.

 

And, that is related to racing, Trans Am, SCCA, the 302, the 305, the fact that Pontiac LICENSED THE NAME but didn't RUN THE RACE (talked the talk but didn't walk the walk), ... ???

Doesn't too much matter though. I think we all digressed from the OP's question somewhat, including myself. I apologize.

I still don't think he has what he claimed. And the answer to his original question is still "no". But we probably won't ever get to hear about any of that anymore since none of us in here bowed down and worshipped. :notworthy: Yeah we used to have a smiley for that, not sure when it disappeared.

 

You're probably right; I shouldn't have been so hard on Pontiac about racing heritage. After all, they DID have a GREAT run in NASCAR in the late 50s; dominated for acoupla years in there if memory serves. 57, 58 range. The old 370. Won the championship acoupla years later, Fireball Roberts driving IIRC. I never had one of those; closest I ever had was a 59 389, a 63 Tempest, 64 Bonneville, 66 (or 7? too long ago to remember) LeMans. I quit buying em after that. Which incidentally the 59 was a very strong runner, 389 4-spd automatic, even if mine was only a 2-bbl one. (a mere Catalina) I have fond memories of that 59. Some virginity was lost - well, maybe not lost, just, temporarily misplaced - in that car.

 

Underrated thread. 10/10 would recommend. OP unfortunately had knowledge bludgeoned into him. Actually, we all did.