big block engine code help - The 1947 - Present Chevrolet & GMC Truck Message Board Network

robby · 03-07-2004, 12:54 AM

can anyone help with my new big block codes?
pad in front of passenger head C8F 329409
on pad above timing cover TD8 121 TST

Any help would be great!

It is supposed to be the original 454 out of the 78 pickup I have.

superchevy · 03-07-2004, 01:17 AM

Get the numbers off the rear of the block above the bellhousing on the drivers side...that is the casting number. The numbers on the pass side are the date codes. Then go here http://www.mortec.com/bbc.htm and see what you have.

Rod · 03-07-2004, 01:29 AM

I like decoding them with the suffix codes... you can find yours here... http://www.nastyz28.com/sbchevy/spcoded.html
78 454 from 3/4 or 1 ton 250 hp.

The site has good decoding information

nez71 · 10-07-2006, 01:39 PM

Thanks that confirms it, at least is says its an original 402 that came in a 1970 GMC pick-up. The lady i bought the truck from said her husband bought it new in 1970, she said he pulled a 21 foot boat and it had a big 10 foot cabover camper on it that was put on shortly after they bought it and never taken off (until I got it). She said her husband wanted more power from it when pulling the boat and camper so she said he had an RV cam put in it to get more power for the mountains. She said it was only used to go to the lake fishing on the weekends. The interior is almost perfect cause the camper shaded it for all these years. the odometer reads only 58000K but the speedo cable is removed from the factory cruise so the speedo dosnt work. Im assumning it has less than 100K original miles, the little lady said it had sat for several years since he died. I drive it as my daily driver with no problems but a slow tranny leak from the linkage for the shifter. Sorry to ramble but I thought it was a good story to share.

Heres a link to a couple pics. Thanks again for the info guys!!!

http://pg.photos.yahoo.com/ph/nez71/...KwonFBgU7ZqHxR

03-07-2004, 12:54 AM	#1
robby Semper Fidelis Join Date: Dec 2001 Location: Cedar City, Utah Posts: 654	big block engine code help can anyone help with my new big block codes? pad in front of passenger head C8F 329409 on pad above timing cover TD8 121 TST Any help would be great! It is supposed to be the original 454 out of the 78 pickup I have. __________________ 72 Chevy C 20 with 402 For sale 85 GMC K2500 83 Trans Am Cedar City, Utah (Missouri Native)

03-07-2004, 01:29 AM	#3
Rod Join Date: Dec 1999 Location: Eastern - Manitoba Canada, Winnipeg Posts: 4,369	I like decoding them with the suffix codes... you can find yours here... http://www.nastyz28.com/sbchevy/spcoded.html 78 454 from 3/4 or 1 ton 250 hp. The site has good decoding information __________________ Senior active founding member. 70 3/4 ton GMC Suburban 4x4 250/4 spd. 71 1/2 ton Suburban Chevy 4x4, 350/350 72 Chev 1 ton tow truck 402BB w/Holmes 440 wrecker on propane 2005 FLSTSCI Harley Springer 85 FXSB Harley Lowrider 72 Triumph 650 Bonneville 5spd "Poor people don't have hobbies" Quote from wife.

10-07-2006, 01:39 PM	#4
nez71 Registered User Join Date: Sep 2006 Location: penn valley, ca Posts: 5	Re: big block engine code help Thanks that confirms it, at least is says its an original 402 that came in a 1970 GMC pick-up. The lady i bought the truck from said her husband bought it new in 1970, she said he pulled a 21 foot boat and it had a big 10 foot cabover camper on it that was put on shortly after they bought it and never taken off (until I got it). She said her husband wanted more power from it when pulling the boat and camper so she said he had an RV cam put in it to get more power for the mountains. She said it was only used to go to the lake fishing on the weekends. The interior is almost perfect cause the camper shaded it for all these years. the odometer reads only 58000K but the speedo cable is removed from the factory cruise so the speedo dosnt work. Im assumning it has less than 100K original miles, the little lady said it had sat for several years since he died. I drive it as my daily driver with no problems but a slow tranny leak from the linkage for the shifter. Sorry to ramble but I thought it was a good story to share. Heres a link to a couple pics. Thanks again for the info guys!!! http://pg.photos.yahoo.com/ph/nez71/...KwonFBgU7ZqHxR

03-07-2004, 01:17 AM	#2
superchevy Got big-block? Join Date: Jul 2000 Location: Austin, Texas Posts: 2,453	Get the numbers off the rear of the block above the bellhousing on the drivers side...that is the casting number. The numbers on the pass side are the date codes. Then go here http://www.mortec.com/bbc.htm and see what you have.



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