So I just bought a 1967 Firebird 400 and I am trying to figure out what engine it has in it. There is an envelope with a bunch of receipts and a hand written note about the engine. It says, "77 Pontiac 400 6.6 Motor. Stock except a RV cam 268 intake 271 exhaust .447 lift 110 lobe centers" Sounds fine, but the numbers are as follows... Engine Code is YU. The casting number looks like 500557. The date code looks like I307. The only number I am sure of is YU. The other ones have been painted over and are a bit hard to read. The heads are 7K3, which would be 1972, 96 cc.
The YU code and the others don't seem to match. Any thoughts?
I am no expert on engine no`s, maybe Q or Banshee will chime in on the date and casting no`s, but I do see in my little 'redbook' that YU is a `78 6.6 L V8 4bbl auto. engine ,was listed to have 180 hp and was supposed to come w/ 6X heads, but you already know what someone replaced those with... (78 they also came w a 6.6 L Olds engine)
500557 is a 75-6 400 block casting code. YU for 1977-8 model year is block casting 568557. Possible that 76 overage went into early 1977 and the I (Sept.) is an early casting #. So the block is a 77 block for a 78 model year car.
The 7K3's are good heads..but will only yeild you 8 to 1 with the 400.
The cam will be fine for a low compression motor, but if you decide to go to smaller chamber heads, you should change the cam.
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1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
Great. Thanks for the help. The casting number could easily be 568557. I looked again last night and I am still not sure...
The car did come with some extra parts including another set of heads. The heads look to be 13 with a date of F259. So if I looked it up right they are 72 CC heads which should be a lot better than the 96 CC heads. So my next question is are the 13's good heads?
Here is a pic of the old bird in case you are interested. Firebird pic
Those heads and a 400..Sure would be fine with proper cam, carb, intake and rear gear selection.
If you do not have an intake yet, a 4234 or 0140 Pontiac cast iron would do (stay away from later egr) also a 750 q-jet (or equivalent) A Comp Cams revised Pontiac grind would be recommended.
I would wait on cam until you know for sure what rear gear you would have.
The motor with those heads will be up there in compression, so you may need to blend fuel.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
