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69 vette help needed

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RHD.68.l89:
5300 RPM = 300hp (base)
5600 RPM = 390HP, 400hp (L36, L68)
6000 RPM = 350hp (L79)
6500 RPM = 430hp 435hp L71, L88, L89, ZL1

This is valid for 67-69 models.
;42

69VETTE:
[.BUT hes giving it the final once over for s.a. lhd rego.....and heres where it becomes funny???
the engine doesnt have an engine number??? its gone,the only number he found somewhere on motor(i dont know i didnt ask) tells him the engine was made in july 1970....so it cant be a 427????  [/quote]

Nifty,

Its most likely the motor is a 427 engine in the car which has been replaced somewhere down the line under the manufactures warranty.  

I have read somewhere in my books that this was a common fault (ie: motor would fail under harsh driving conditions) and when the dealer replaced the engine, they didnt replace the exisitng numbers on the replacement motor.

Which were supposed to be stamped by the dealer after replacement.

If your friends 69 vette was built in the last say two months of production, then it could also be a 454... (this would be unlikely and rare) but in all events i would go with what RHD.68.189 advised.

Check if there is any casting numbers at the rear of the block (which it should have)?  These are usually found to the rear left hand side near dizzy... they can also be usefull..

M;36

nifty:
block casting 3963512
casting date c.25.70
it has a redline of 5600rpm

69VETTE:

--- Quote ---Originally posted by nifty
block casting 3963512
casting date c.25.70
it has a redline of 5600rpm
--- End quote ---


Hello Nifty,

I have been doing some searching and the following was discovered:

OK.. from 69 Stingray Guidebook by Rick Bizzoco the following:

Block Casting 3963512 was used between 1969-71 and is for a 427 motor. Not 454.. sorry.  However they were also used in 1970 cars.  These blocks were for 400,435 & 430HP motors (4 Bolt Mains).

On the ohter hand the casting No C25.70 refers to C=March 25= 25th day and 70= 1970.

Hence the block was cast in 1970... ?

Whats the Vin No on the car Nifty?  I can check the date etc if you like.

Now, the above also matches another great book called Corvette by the Numbers by Alan L Colvin, which says that this block was used in mid 1969 vettes through to 1971.

If it was cast in 1969 its a 427 (390HP = 2Bolt mains, or 400, 430 & 435Hp= 4 Bolt mains) and if it was cast in 1970 its a 454 block (390HP= 2 Bolt).

So take your pic!

Given that it was cast in in 1970...its likely the original motor was replaced in 1970 with a 390HP 2 Bolt Mains motor.

The only way to really now for sure is to pull off the sump and check to see whether its a true 4 bolt mains.

Nifty, either way its still a L71.

I hope this helps ;30


M;36
 






T

RHD.68.l89:
From the redline the car was NOT originally an L71. (This is the redline and not the orange line we are talking about. On an L71 the orange area starts around 5600.)
Check if it has a return line to the fuel tank.
If it has a return then it had a Qjet and was a 390hp L36.
If it has only the feed line then it is a L68 and 400Hp.

The 512 block was used in 2 and 4 bolt mains and 427 and 454 applications. I would guess someone has replaced the original block with a block which has the correct casting number but the wrong date code. Depends on whether they replaced the whole motor or just the block. Have a look at the balancer to see if it is externally balanced. This will tell you if it is 454 or 427.

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