Engine year

[mgtdsteve]

I have a 1978 Avanti 2 which is all stock. In order to order parts, is the 350 engine a 1978 also. Thanks, Steve

[Gunslinger]

The short answer is...probably.  Avanti Motors purchased engines in groups to get quantity discounts.  The engines didn't necessarily get pulled in order of receipt as well as any particular engine might have been say...a '77 engine that wasn't installed until '78.  Most car manufacturers install their engines into new production within weeks of being built...Avanti Motors wasn't like that as engines sat in inventory until needed.  

More than likely your engine is for a '78.  The only way to be sure is get the engine numbers and casting numbers to decode when it was originally cast.  Still...like all carmakers, Avanti Motors had to certify the engine had to meet all applicable regulations at the time the car was built.  

Another thing to look for...is your engine painted orange or blue?  1977/1978 was the period GM changed all engines from whatever division to Corporate Blue.  If your engine is painted Chevy Orange, it's a '77 production.  

[Jim78]

On the front of the right side of the engine block, behind the alternator (may require removal) there is a stamped number.  Copy this number and google "SBC engine codes".  There are several sites such as  http://www.nastyz28.com/sbchevy/sblock.html

These will decode into the manufacturing plant, date, and suffix code.  For instance, my '78 (blue engine) code is V1001CLM which tells me that it was built in the Flint plant on October 1, 350 AT, L48 185HP, Corvette/Monte Carlo. 

It is equipped with ignition static shielding, as would be the Corvette.  All that said, if you look at '77 or '78 Corvettes with the L48 you will see that the alternator is on the left side, and the A/C compressor is on the right.  There may be other variations, but it appears that most of the rest is the same.  Note that the chrome air cleaner top is not original to the engine, but IMHO looks much better.  Got that from "Corvette America", reasonably priced.

Note that the date code indicates a month and day, but not a year.  Since my Avanti was shipped from the factory on Sept. 26 1978, the October motor date makes it 1977.  If you have a valve cover off, there is a number on the cylinder heads, too.  This number defines the model of head, and a manufacture date, including the year.  Mine is Nov 10 1997, which makes sense with the date on the block. 

PHOTO DELETED DUE TO ATTACHMENT LIMITS

 

Edited November 4, 2019 by Jim78
add'l info.

[mgtdsteve]

Thanks for the help. It is painted Blue, has the chrome Ignition covers and the numbers confirm it is a 1978 engine.

[Avanti83]

If the parts you refer to are external parts, then forge ahead but you are still in the bad performance/emissions years of the SBC. If you are doing a rebuild using 78 spec parts, do yourself and your Avanti a favor and ash can the cam, cam gear and possibly the carb. 

A decent street performance cam and new cam gear will take the bad timing and performance from the old engine to a much better level of preformance and driveability. A new carb will give you tune-ability to allow the new parts to perform well.

Realistically, SDC's were very similiar until about 98. 

Edited June 17, 2018 by Avanti83

[Jim78]

Additionally, check the cylinder heads.  The numbers can be seen with the valve cover removed.  The "XXX624" heads are some of he poorer performing, and are prone to cracking.   There is much information about SBC heads on line.  Google is our friend.  It's all about how deeply you want/need to get into a rebuild.   At some point, a crate motor becomes a good idea.