Guys, A question that I need help with. I have a cast iron 3 deuce intake off a 348. Numbers are; 3749948 GM 2 B2460 I take it that it is a 1960 intake, February. Did a 409 use this intake also? Did this same intake get used until 1962? Thanks
3 X 2 intake was 348 only. 409's went to single and 2 X 4 aluminum intakes for the performance models. But that was for the big heads.
While Larry is correct about GM not using the 3 x 2 on the 409....as long as the small port (348 or 409) heads are used, that manifold will work fine on the 409. They have the same deck height. Mike
If you wanted it to be a "cheater" engine you could run the 3x2 setup on a 409 but you would get "Nice 348" all day long from guys looking at it.
Guys, Thank you for your knowledge, I suspected that was the case. How long would that date code have extended in production runs? Did GM make a run of these without changing date codes? In essence, would it be correct for a 61 348? Thanks
According to my reference book, that casting number was used from '58-'61. The casting date would have only been used on that day as I suspect they changed the date in the mold every day. I'm guessing that they didn't make all the "tri-power" manifolds for the year in one day. In my opinion and from my exposure to engines/date codes, I think an August date would be about as early as you could expect for it to be for the 1961 model year. About date codes in general, I have rarely seen the dates on the block and each cylinder head match exactly.
I've got a customer that has an original 63 409 Impala. His deal is that he has the production date of the car and all of the casting numbers need to be in a certain time span before the production date of the car. So the casting numbers would have to be pretty specific for an individual car, and (as I understand it) the production dates changed everyday.
On low production performance cars, the date codes for 4-speed trannies, specialty blocks, heads, rear axles are often months earlier than the car build date. Then, there were replacement parts added years later. What GM usually did is when a part was discontinued, a la the 348" tri-power, they'd guesstimate how many might be sold in the next ten years and run those for stock. I knew of one old-lady-owned '58 Impala convert which had the tri-power removed. She never used full throttle, so the rear carbs were always stuck. The second owner wanted it back, but the parts counter manifold and carbs had late '61 date codes. BTW, 348" heads and tri-power on a 409" truck engine make a great street puller for a heavy ride. Great low end torque, good fuel economy and dead smooth up to 5,000 RPMs. jack vines
Pistons, cam, and bigger valves will make a nice start to a good street engine. This one started life as a truck engine.
Nothing, most of the low compression is in the pistons in the truck engine. Seems like the relief in the block drops the compression about .5 and the recess in the 333 heads about .25. So if you use Ross 11:1 pistons you still come out with plenty of compression for the street. We used one piece stainless intake and exhaust valves, cut out the valve pockets, pocket ported and matched the intake ports to the 2 X 4 intake (took LOTS of grinding). Used an Isky cam (I'd have to dig out the specs, but similar to a Z-11), balanced the rotating assembly and all the other usual tricks. BTW, this is a different engine than the one in the 63 I mentioned above. It's a numbers matching deal with partial VIN and all.
Chevy was the only GM car that did not go to the big end carbs on the tri power equipped cars in 1959. The 348 used the small end carbs on the tri power until they stopped using them. The GM engines started getting bigger and so did the tri power end carbs. You might be pushing it on a 409. If you have one of the original tri power 348 air cleaners, it's worth more than the rest of the set up. Those 348 tri power carbs can be used on a aftermarket tri power manifold for a SBC.
54 Nomore, In searching the web, I did find a 5 3 deuce manifold, it had different markings/letters, and did not say GM 2. I am assuming that the Feb 60 date code, means it was for a 1960 348 car? Rather confusing.
So what your friend is saying, is that the GM foundry would cast new parts daily? Wouldn't that get out of hand real quick, with many different cast iron parts in cars back then? Still wonder if they would make a run, of lets say 100, and when that same supply was running low, redate the cast number in the mold, and then 100 more. Thinking out loud.
Packard V-8, I now truly believe that your first two paragraphs above, and LarryT, and 54nomore posts answered my questions, thanks guys !!!
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