454 block decoding - The 1947 - Present Chevrolet & GMC Truck Message Board Network

STOCKISH · 04-03-2009, 04:33 PM

Is there a chance anyone could help me decode a block. I have the numbers from the block and heads.
On the block
3999289

t0212trh

c4f154804

On the heads the casting is
336781

Any help would be greatly appreciated. Also, are these heads and block good for a ~400-500hp build? Thanks

DMARCUM123 · 04-03-2009, 04:55 PM

the block is a 71-79 block could be a 2 or 4 bolt main and the heads are oval port 118cc chamber 256/114cc ports they are great for a street motor they cna be rework for the bigger valves and have them open up bowl out and blended good set of heads yes you can get 400 to 450 easy 500 and up things change for the cost i would do the 496 storker thats what i have 550 to 600 hp

DMARCUM123 · 04-03-2009, 04:57 PM

72 if you need parts theres a buddy of thats all he has ever race and deals in so need something let me know i can give you his number

shooterpcb · 04-03-2009, 05:41 PM

That block with the TRH suffix code was used in 1973 & '74 in 2wd TH400 transmission pickup trucks and in 1978 and 1980 in 1 ton 4x4 manual trans trucks. ranging from 225-250hp. Remember this was with small camshafts and cast iron exhausts. The 781 heads are worthy and capable of 375-450hp easily in my experience with a few upgrades. Using a good street/strip .570-.650 lift cam, a 850cfm carb, headers, a good ignition, a good aluminum intake and pistons with a small dome on them for more compression in open chamber heads, you can make alot of power with this motor. If you wanted to, you can start with the cam, headers and pistons and make alot of street performance with the stock intake and tuned carb. Whatever your intentions and budget allows is the key. Also make sure you use an OVAL port intake if you use those 781 heads. There are 3 types of intake runners on Chevyy big blocks, so make sure you get an oval intake. There are small ovals and rectangled shaped intake runners also.

STOCKISH · 04-03-2009, 09:44 PM

Not sure on the suffix code though. The block and heads both say passenger high performance.

shooterpcb · 04-04-2009, 12:45 AM

all of the Mark IV big blocks 396,427 and 454 say that on them as long as they are not a tall deck block.

eightbanger · 04-04-2009, 08:53 AM

This is the site I used to decode mine
http://www.mortec.com/bbc.htm

04-03-2009, 04:33 PM	#1
STOCKISH Formerly- 1972SuperCheyenne Join Date: Oct 2008 Location: Wake Forest NC Posts: 5,782	454 block decoding Is there a chance anyone could help me decode a block. I have the numbers from the block and heads. On the block 3999289 t0212trh c4f154804 On the heads the casting is 336781 Any help would be greatly appreciated. Also, are these heads and block good for a ~400-500hp build? Thanks __________________ --Josh My Build Thread:http://67-72chevytrucks.com/vboard/s...d.php?t=799218 A good crossthread is better than Loctite any day. Life is not about what you have, but who you have to share it with.

04-03-2009, 04:55 PM	#2
DMARCUM123 Registered User Join Date: Sep 2006 Location: WAYNE, WV. Posts: 675	Re: 454 block decoding the block is a 71-79 block could be a 2 or 4 bolt main and the heads are oval port 118cc chamber 256/114cc ports they are great for a street motor they cna be rework for the bigger valves and have them open up bowl out and blended good set of heads yes you can get 400 to 450 easy 500 and up things change for the cost i would do the 496 storker thats what i have 550 to 600 hp

04-03-2009, 04:57 PM	#3
DMARCUM123 Registered User Join Date: Sep 2006 Location: WAYNE, WV. Posts: 675	Re: 454 block decoding 72 if you need parts theres a buddy of thats all he has ever race and deals in so need something let me know i can give you his number

04-03-2009, 05:41 PM	#4
shooterpcb Registered User Join Date: Aug 2007 Location: alabama Posts: 72	Re: 454 block decoding That block with the TRH suffix code was used in 1973 & '74 in 2wd TH400 transmission pickup trucks and in 1978 and 1980 in 1 ton 4x4 manual trans trucks. ranging from 225-250hp. Remember this was with small camshafts and cast iron exhausts. The 781 heads are worthy and capable of 375-450hp easily in my experience with a few upgrades. Using a good street/strip .570-.650 lift cam, a 850cfm carb, headers, a good ignition, a good aluminum intake and pistons with a small dome on them for more compression in open chamber heads, you can make alot of power with this motor. If you wanted to, you can start with the cam, headers and pistons and make alot of street performance with the stock intake and tuned carb. Whatever your intentions and budget allows is the key. Also make sure you use an OVAL port intake if you use those 781 heads. There are 3 types of intake runners on Chevyy big blocks, so make sure you get an oval intake. There are small ovals and rectangled shaped intake runners also. __________________ 1968 C-10 2wd, short bed fleetside, 355 Chevy, TH350, 12 bolt pegleg, '81 Camaro cowl induction on hood(I don't like it, previous owner did it), 10" wide 15"wheels.

04-03-2009, 09:44 PM	#5
STOCKISH Formerly- 1972SuperCheyenne Join Date: Oct 2008 Location: Wake Forest NC Posts: 5,782	Re: 454 block decoding Not sure on the suffix code though. The block and heads both say passenger high performance. __________________ --Josh My Build Thread:http://67-72chevytrucks.com/vboard/s...d.php?t=799218 A good crossthread is better than Loctite any day. Life is not about what you have, but who you have to share it with.

04-04-2009, 12:45 AM	#6
shooterpcb Registered User Join Date: Aug 2007 Location: alabama Posts: 72	Re: 454 block decoding all of the Mark IV big blocks 396,427 and 454 say that on them as long as they are not a tall deck block. __________________ 1968 C-10 2wd, short bed fleetside, 355 Chevy, TH350, 12 bolt pegleg, '81 Camaro cowl induction on hood(I don't like it, previous owner did it), 10" wide 15"wheels.

04-04-2009, 08:53 AM	#7
eightbanger 454 MAKES IT ROAR Join Date: Jan 2008 Location: Essex, U.K Posts: 2,701	Re: 454 block decoding This is the site I used to decode mine http://www.mortec.com/bbc.htm __________________ Nigel. An American living in a British body. 1971 Chevy Cheyenne 10 454 "In a time of universal deceit, telling the truth becomes a revolutionary act." - George Orwell "When injustice becomes law, resistance becomes duty" - Thomas Jefferson No more pain. 03.12.60 -- 12.28.10 http://www.youtube.com/Eightbanger

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