84 V6 - 2 different CRs? (8.4:1 or 8.9:1)

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LoadHawg - 24 Apr 2005 23:33 GMT

My '84 Firebird came w/ the LC1 engine (Code '1' in 8th spot of VIN) that is an 8.4:1 CR.

Apparently there was another V6 in '84 w/ slightly higher CR (8.9:1) - Can anyone tell me more about this slightly
higher CR V6?

thanks,

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Andy Warren - 25 Apr 2005 00:04 GMT

In 1985 the 8.5 C/R LC1 2.8L @ 107 hp was changed to 8.9 C/R LB8 2.8L @ 135
hp. This lasted until 1990 and the introduction of the 8.5 C/R LH0 3.1L @
140 hp which was used until the 4th gen came out. I don't know which parts
will swap between the 3.

> My '84 Firebird came w/ the LC1 engine (Code '1' in 8th spot of VIN) that
> is an 8.4:1 CR.
[quoted text clipped - 4 lines]
>
> thanks,

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LoadHawg - 25 Apr 2005 00:40 GMT

So in '84 they offered BOTH a 102hp 8.5 C/R AND a 107hp 8.9 C/R 2.8L V6?

Mine was the LC1 (8.5 C/R w/ 102hp)

What was the RPO code on the 107hp higher C/R V6?

thanks,

>In 1985 the 8.5 C/R LC1 2.8L @ 107 hp was changed to 8.9 C/R LB8 2.8L @ 135
>hp. This lasted until 1990 and the introduction of the 8.5 C/R LH0 3.1L @
>140 hp which was used until the 4th gen came out. I don't know which parts
>will swap between the 3.

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Andy Warren - 25 Apr 2005 01:24 GMT

No. Depends on whos specs you look at if the 8.5 LC1 was 102 or 107 HP.
There may be an error in your spec sheet for the LB8. It is listed at 8.9
&135 hp for each year it was used. Supposedly the LB8 wasn't installed until
the start of the 85 model year. But you know GM, ever heard of a 1968&1/2
firebird? (or is it a 1969&1/2)

> So in '84 they offered BOTH a 102hp 8.5 C/R AND a 107hp 8.9 C/R 2.8L V6?
>
[quoted text clipped - 9 lines]
>>140 hp which was used until the 4th gen came out. I don't know which parts
>>will swap between the 3.

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LoadHawg - 25 Apr 2005 05:45 GMT

Yep I know how GM can be. ... ;)

All I'm going by is the '84 Pontiac Firebird's Owner's Manual:

It lists 2 V6s. One they call the '1' engine and the other they call the 'L' engine. The 1 or L come from teh 8th spot
in the VIN. The '1' engine is listed as 8.5 CR and 'L' as 8.9 CR.

To be honest I'm not familiar with the LB8 engine and was wondering if both CRs could possibly be for the LC1 ... ? Or
maybe the LB8 made an appearance in '84? Dunno - just speculating...

thanks,

>No. Depends on whos specs you look at if the 8.5 LC1 was 102 or 107 HP.
>There may be an error in your spec sheet for the LB8. It is listed at 8.9
>&135 hp for each year it was used. Supposedly the LB8 wasn't installed until
>the start of the 85 model year. But you know GM, ever heard of a 1968&1/2
>firebird? (or is it a 1969&1/2)

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