Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
I am very sorry for the long wait
can you tell me what the casting numbers are drivers side rear of the engine block top
like this picture here for the location of those casting numbers
that is correct but the problem i am having with that stamp number is ***** never made a block with the suffix code AA8
can you double check that stamp ?
also the reason for knowing the casting number is ***** will help us to narrow down the year of this block to help us find out what year ect..
but as of now there is NO AA8 ever made
so i need that stamp rechecked and the casting number to help you out
ok just using the casting numbers to narrow this down this block is from a 1978 to a 1990 2 or 4 bolts main ( which i am sure you knew )
14015445...454.......78-90...2 or 4 bolt
the problem you have is the TM which usually is a stamping used for a target master replacement over the counter engine
and with AA8 which was NOT a stock code stamp
GM did not keep any records for any replacement engines for any stamp coding for these replacement engines
the engine is a generic replacement 454 that fits 1978 - 1990 cars or trucks
with no records it will be unknown on the exact year of this engine or HP I am sorry to say
i know this is what you did not want to hear but that is what those stamp numbers and letters mean when they start with an odd 2 alphabet numbers and end with a stamp number not documented
any stock 454 engines started with stamp code AKA and went up from there
Your engine is a 1978 LS6 454 crate engine.
Just for clarity of detail. XAA is a code for a 10.2 / 1 compression crate engine. Internally the XAA motors are exactly the same as the earlier higher compression LS6 motors.
T = Towanda
XAA = LS6 crate engine suffix code
The XAA engine ...sold with the P/N 366250 came with iron, rectangle port, open chamber heads & 2.19 1.88 valves.
454 LS7 suffix is XCH.
Yes, it is a 4 bolt main.
Give me the casting number and I'll look it up for you.
The casting number is(###) ###-#### ***** is the information:
425HP, 118.0cc, IP 325cc
RECTANGULAR PORT - Valve size
2.19 intake, 1.88 exhaust
IP = Intake runner volume
It is an LS7 head. The casting number is(###) ###-####for the LS7 Cast Iron open chamber heads. OTC Crate LS6 engine assemblies, got the cast iron OTC crate LS7 Open Chamber head installed to late 80,s . GM did this to lower the 11. to 1 Compression to around 9.6 to 1 because of piston damage due to diminishing poor fuel octane rating.
Description of this head is as follows: Open Chamber LS-6 & LS-7 Service Head.See: http://www.corvetteforum.com/forums/c3-tech-performance/271365-i-d-my-heads-today-anyone-tell-me-about-these.html#ixzz3nU4JrC
They're basic over the counter service replacement open chamber heads.They were not specifically LS6 or LS7 heads, they were service replacements.
See forum link: http://www.camaros.net/forums/archive/index.php/t-90422.html