New poster here. I have just acquired a 55 Chevy with a LS376/480 crate engine. I have no documentation to verify that, is there any way to externally tell if it is a 430 vs 480? (yes i have searched this forum a bunch but no luck) Builder is no longer in existence. I understand that the only difference is the cam and i checked GM's crate engine site and both have the same block part numbers (12623967) Interesting in that the only stamped number i could see at the rear drivers side of the block is 0310663? It looks like my setup has the standard GM Erod harness and controller. I reckon i could disconnect the controller and check the PN on the rear of it as the 430 supposedly has a different controller than the 480 as far as part numbers...I'm assuming those numbers would be on the rear tag of the ECM? Just trying to verify what i have as i am having a driveability issue with the dreaded surge from 1700-2500 rpm (manual Tremec tranny). I know from this forum that is common with some modded LS engines but i am told by others that a stock Crate engine with GM controller should have no such issue and that tuning is not the answer. Also I'm pretty sure there is not a stock ECM tune as this was running poorly before i acquired it, the car was sent to a tuner (Mass Acceleration Motorsports) and they had to "Unlock" the ECM and then they dyno retuned it. They indicated that a stock ECM would not be locked so they figured it had an aftermarket tune?
That was immediately before i acquired it...unfortunately what they did was ineffectual as it ran on only 4 cylinders when i got it. 2 main problems a stuck 02 sensor was resulting in a fuel trim of 50 on one bank thus totally flooding that bank out. Then it was discovered no fire to coils on the same entire bank...faulty wiring to a critical connect pin that provided power to the coils.
Anyway it's looking like i may have to try another tuner to iron out the surge.
But to my original question....I'm assuming there is no way (externally) to tell if 430 vs 480, one reason is i want to verify that i have the correct ECM installed since they are different or at least have different programing. Anyway this has been the crappiest running car i have ever had and i have had some real POS cars and some highly modded ones as well.