labrat Posted May 9, 2002 Share Posted May 9, 2002 ok guys, here's the deal. I have a 72 model 350 from a pick up in my 81 280ZX right now, but as it was pretty much a wrecking yard motor I installed without really checking it out, it needs a rebuild. My friend just ran into a good deal, and he's offering me a 302 chevy from a Z28 with a blown headgasket for 300 bux. Now, i know this motor will need a rebuild too, so my question is, is it worth it to go for the high revver? I have the non-turbo ZX with a 3.90 r200, so i'm thinking this might be the way to go. Just kill the low end torque and go for top end balls. I guess the bottom line is, all things being equal, which would you go for? I'm leaning towards the 302, but that's mostly for uniqueness, i guess. Conversely, i'm sure parts will be more expensive. Is this a good price for the motor? Any feedback would be greatly appreciated! Bill Quote Link to comment Share on other sites More sharing options...
Guest zfan Posted May 9, 2002 Share Posted May 9, 2002 If its a true DZ302 I would jump all over it. They listed horsepower at 290 I believe but it was closer to 350/375 hp. That is a absolute screaming motor. Revs to the sky,rebuild would not cost much more than the 350 I would think..its all GM. Should have double hump heads 2.02/1.60's. Make sure and check casting numbers just to be sure your getting a DZ302. Mike Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted May 9, 2002 Share Posted May 9, 2002 A question similar to this has gone around this site several times. Here is one thread: http://www.hybridz.org/ubb/ultimatebb.php?ubb=get_topic;f=1;t=001961 I got into a discussion with Grumpyvette about heads and flow capacity and we touched on this. I grew up wanting a 302 out of a 1969 Camaro and was headed in that direction for my Z. But since no one seems to sell 302 parts it is looking like it will be cheaper (and have more horsepower potential) to go with a 350. Unless I miss my guess that 302 is a very rare motor. Chevy only offered it for a couple of years and even then it was only popular with a certain class of racers. If someone has numbers please correct me. If the rest of the engine is in good shape and fairly complete you could have a living piece of history. Let me know if the engine has the cross ram, dual 4 barrel carb set up. If it does I'll come to Texas and pick it up! Quote Link to comment Share on other sites More sharing options...
Peternell Posted May 9, 2002 Share Posted May 9, 2002 Zfan is right. If it's a DZ motor (engine code) then jump on it, regardless if you plan to use it or not. Yes a 302 will cost quite a bit more to rebuild than a 350, but sell the 302 to someone looking to restore a 67-69 Z/28 and you'll be bucks ahead! If you really want a 302 put a 283 crank in a small journal 327 block, but don't loose the inherent value of an original DZ motor. For the right person thats a $1,500-$2,500 engine. Take the money and run. If it's not an original DZ engine, then ask some questions like: Is it a 4-Bolt block, which would work great for a 350 build and what's the bore and what will it clean up at? Are the heads good [ie camel hump: 462, 291, 186, 492) or the (68 only 040's)]? Is it a steel crank and if so what is the stroke? Many people "think" they have a 302 but it's a 283 or 327 or a plan old 350 (heasven forbid a 305) or a small journal 283/327 combo. Look closer. Quote Link to comment Share on other sites More sharing options...
labrat Posted May 10, 2002 Author Share Posted May 10, 2002 Well, i ran the casting numbers on the block and heads, and it is indeed a DZ302 block, but has stock 350 truck heads and an edelbrock aluminum manifold. I know it has a blown headgasket and was driven "hot" for a while (far enough to get home when it blew), so i know it will need a rebuild, and i will be putting aftermarket heads on it, so i'm adding that to the price equation. I believe the motors came stock with forged pistons, so that's another check in the "for" column. The feedback from here has been positive, so for the price, i think I'll jump on it. Thanks guys! Bill Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted May 10, 2002 Share Posted May 10, 2002 Shoot. And I was checking road maps for the driving time to Texas! Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 11, 2002 Share Posted May 11, 2002 That 302 (Duntov) in the original Z 28 would forcibly pin you to the back of the seat between 50 to 90 mph . You could not even blink your eyes properly until 100 mph and the engine wound forever in third gear. Quote Link to comment Share on other sites More sharing options...
jt1 Posted May 11, 2002 Share Posted May 11, 2002 Peternell is right about the DZ block being valuable to the camaro guys, and he's about right on the price. That is a major score. I'd find a good buyer for the DZ, then put that money on a early 4 bolt block and lots of other goodies. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 11, 2002 Share Posted May 11, 2002 A few years back , I was at a garage sale and there was this strange GM cross ram dual 4 Barrell manifold with carbs and air cleaners linkage. The guy wanted $40.00 because he could not get them to work right on his chevy . A friend of mine told another guy who raced over there and bought what was a rare option on a Z28 302. If I only Knew what I know now about Chebby's Day late and a dollar short Git on that piece of automotive history. it is rare and one heck of a motor Quote Link to comment Share on other sites More sharing options...
labrat Posted May 11, 2002 Author Share Posted May 11, 2002 Well, i would grab it just for the investment, but as this is a friend and he is doing me a favor, i couldn't buy it to just to sell it. He'll give it to me at that price if i put it in my car, but not if i'm gonna resell it. I'm thinking that's what I want to do, though. My plans so far are small chamber heads (prolly darts or canfields) w/girdles, a manifold somewhere between a performer rpm and vic jr., with roller rockers and a solid roller cam. I wanna be able to creep around town without havind drivability problems, but i want it to scream like a banshee in the upper end. Quote Link to comment Share on other sites More sharing options...
Mike C Posted May 11, 2002 Share Posted May 11, 2002 Since a 302, 327 and 350 large journal motors all share the same block, until you check the casting number on the crank to make sure it is a 3.00 stroke, no guarantees the motor is STILL a 302 regardless of what it started life as. Anyways, for the money it is a fair deal for a running motor even if it were not a potenial collector item. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 12, 2002 Share Posted May 12, 2002 OK, now I'm seriously confused.... When I bought the car the guy said it was a 327. I ran the casting number at MorTec and it says 69 350. I go to nastyz28.com and it says either 302 or 350. Sooo, how can I find out for sure. The way you guys describe the 302 sounds like my engine. It friggin screams at highway speeds. BTW, the casting number is 3932388. Thanks for your help. Quote Link to comment Share on other sites More sharing options...
labrat Posted May 12, 2002 Author Share Posted May 12, 2002 mods, please delete this one. Thanks Quote Link to comment Share on other sites More sharing options...
Mike C Posted May 12, 2002 Share Posted May 12, 2002 You will not find a 3" stroke crank cheap. Pistons are different as well and the only "cheap" ones are the 4 valve relief TRW forged flat tops, but they are about $350 a set now if they still make them. The 11:1 pistons are still available as the next closest at about $450. Piston pin height change is how the can use same rod and block and maintain quench and deck clearance. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 12, 2002 Share Posted May 12, 2002 A friend of mine has a 327 block with a 283 crank that burnt a couple pistons, I didnt read all the earlier posts, but if you are interested in buying it send me an email. Travis@austincarclub.com Quote Link to comment Share on other sites More sharing options...
labrat Posted May 13, 2002 Author Share Posted May 13, 2002 Just checked the crank casting number, and it's a 350 crank... Damn! Oh well, i guess i'm getting a decent block, anyway. I may just find me a 3" stroke crank and build it up... Any ideas where I could find one good and cheap? Another question, since quench height and compression height are so important, how can you just change the stroke in a motor by up to 1/2 in without having a forceful introduction of piston and head? do the wrist pins connect "higher" up on the piston for the longer stroke cranks? They all use the 5.7" rods, right? This confuses me... Bill Quote Link to comment Share on other sites More sharing options...
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