[Stikman33]

Hey guys, i am in the process of getting a corvette ready to go for a friend. I have posted info on here about it before but now i have some pictures. If you guys would look over this info for me i would really appreciate it. As by my current info it looks like it is a real 1969 Corvette L89 setup. The only thing that doesn't match to me so far is the heads, i dont know why they are 074 castings, i hear they should be something else, but by the block numbers it says that it is. Any help or opinions is appreciated.











Thanks for all the help once again guys.

Daniel

[orange crush]

Daniel,

Looking at the corvette black book, your LP engine code is a 1969 Corvette 427/435 hp aluminum head engine. The 3946074 casting on the head is correct for that engine. The vin# makes it a earlier 69 model as the #' ran from 700000 thru 738762 the vin also shows it being a vette coupe.

Hope this helps,
Bill

[Mike Feudo]

The 074 is the L-88 ZL-1 head. With the closed chamber 11to1 pistons you definately won't have 435HP. I have never come across a real 69 L-89 head but it should be a closed chamber simular to the 392 head. I don't know if they used up all of the earlier heads they had or actually had a different casting but it's not an 074.

[DaleM]

Mortec.com shows the 074 casting for 69&71 rectangle port OPEN chamber (118cc) and idavett.net shows the L89 as an aluminum headed L71 (427/435) as well as the "LP" suffix code correct for a 427/435. Agree with Bill on this one.

[von]

Chevy By The Numbers shows #3919842 to be the correct alum head for a '69 427 L-71/L-89 Vette.

[David Bates]

Originally Posted by von

Chevy By The Numbers shows #3919842 to be the correct alum head for a '69 427 L-71/L-89 Vette.

Agree!

[DaleM]

Mortec shows the 3919842 aluminum head for a CLOSED chamber w/107cc L88/L89. Could both heads be correct?

[Mike Feudo]

67-68 L-88 L-89 are closed chamber. 69 L-88 is open chamber. The 69 L-89 is closed chamber. The L-89 was just a std HP engine with alum. heads nothing else was different.

[sob]

Hey Daniel,maybe this website can help further,post any questions on that motor in the c3 section,my L71 vette was modfied with 1971 openchamber heads with different pistons to help with todays gas,this was done in the mid 80s though I have all the ori. parts, what are the date codes on the heads?Darryl
http://forums.corvetteforum.com/index.php

[Stikman33]

Thanks sob, i will post over there as well. Where are the date codes on the aluminum heads? I didn't see anything readily recognizable on the top of the head, i had heard that for the aluminum heads sometimes the date codes were on the bottoms? Thanks for all the help/comments so far as well...

I had the same thoughts on the heads, i had heard they were supposed to be 842 heads. What is interesting to me though is the block is obviously the LP engine code, and it matches the VIN # of the car. Everything else it has matches as well including the rear end and tranny in the car. I searched the car high and low for a build sheet and have not been able to find anything, so i really dont hope to still find out. He is interested in selling the car eventually, but we are just trying to figure it all out now, and see whether or not its an L89, or an L72 i think it is that is the standard head 435 hp version.

Daniel

[von]

The 435 hp 427 was option RPO L-71. If you wanted that with alum heads, you got RPO L-71 THEN added RPO L-89 which replaced the cast iron heads with aluminum versions. The L-88 was a whole different ball game. No heater or radio, different hood, very limited production car, very different 427 with huge solid lifter cam, 12.5-1 CR, open chamber alum heads, high rise 1x4 bbl intake with no center divider, 850 cfm Holley, etc.

[Stikman33]

Yeah, i have seen the info on the L88 and i dont think this is one... What i am really trying to decipher is whether this was an L89, or its just another L71 that someone put a tri-power and 074 heads on.

Was this deck number exclusive to L89 motors with the LP code, or could the LP code also have been an L71?

Daniel

[orange crush]

Daniel,

To the best of my knowledge and I don't claim to be perfect but the L89 is an L71 with alum. heads, the alum heads make it a L89. The L88 would have a LV engine # so it is an L89.

Bill

[DougA]

I have no idea what any of those codes mean,but I sure would like to go for a ride in it when its done.

[sob]

the LP code confirms that the motor is a L71 with alum.heads=L89 with a 4 speed.and by the looks of the pad,it has never been messed with(original broch marks) some places to find the build sheet,on top of the gas tank,usally on drivers side.between the tack and speedo (you have to take the dash pad off )inside the dash,behind the kick panels,under the carpet in the back storage area, also in the seats.and people have found them shoved in diff. sections of the frame.you can pull down the rubber gas boot and take the gas bezel off and with a flashlight look on top of the gas tank to see if the buildsheet is still glued onto the tank,if it is DONT TRY TO REMOVE IT! drop the tank(only takes 30 mins,)try to dust the years of dust off with a paintbrush and take a pic. of it and reinstall the tank.what I did with mine is I took plastic with duct tape and put plastic over it then reinstalled the tank just to help preserve the build sheet,that looks to be a VERY rare car,Darryl