musman70

Hi,

I'm going to buy a 305 TPI engine from a 1988 Firebird.
I know, that it's the cars original motor, but for some reason it has perimeter style valve covers, not centerbolt...i thought that from '87 centerbolt heads were standard.
Can it still be a roller block with "old" style heads, or is that combination impossible?
Did GM install "old" heads into roller blocks, or does roller block always have those centerbolt covers.....?

-J

Willie

From a historical perspective, all 1987 and newer 305 and 350 TPI's had centerbolt valve covers. There were no exceptions.

Yes, it is possible to install the perimeter style heads on a 1987 & newer roller block. They will bolt on. However, the intake (base) must have the correct bolt hole angle. So with 1986 and older perimeter style heads, a 1985 or 1986 base must be used.

So if you've verified the block as a 1987 or newer roller by the information stamped on the flat surface on the exposed portion of the passenger side deck surface towards the front, the only explanation would be that the heads and base have been replaced. If you have not verified the block, I'd suspect it is not original to a 1988.

------------------
Willie

Moderator
History/Restoration Board
http://www.thirdgen.org

Supercharged 1987 305 IROC-Z, Daily-Driver, Emissions-Legal.
Best E/T: 12.00
Best Trap Speed: 117.69 mph

SC Z!!!

1987 "20th Anniversary Commemorative Edition" Z28 Convertible
305 TPI / 5-speed
Super Chevy Show Class Winner, 1998.

TPLS Z!!!

[This message has been edited by Willie (edited August 20, 2002).]

musman70

Thanks for the info...what should that flat surface say, and is there different code on 305 and 350?

Is there any other way to identify block without taking it out from car...

-J

Willie

The only conclusive way to determine an engine's originality is from the stamping on the surface I described above. Here's an example for 1988:

V 01 14 CHC
1JL100001

V is the plant.
T = Tonawanda
F = Flint (Motor)
V = Flint (Engine)

01 is the month.

14 is the date.

CHC is the engine code.
A 305 can be a CHA, CHB, CHC, CHP, CJB or CJC. A 350 has to be a CUA.

The second line is decoded this way:
1 = Chevrolet
J = 1988
L = Van Nuys
100001 = Production Sequence.

Willie

[This message has been edited by Willie (edited August 21, 2002).]