does anyone have good history or specs for the awesome ls7??thanks,jim

From HPBooks old book, "How to Hotrod Big-Block Chevys"..

465hp.............. And w/ no more than a good tuneup and a good set of headers uncorked, I figure that you are looking at, at least at 600hp!!

12.5 to 1 CR. w/ forged open chamber high dome floating pin pistons w/ 1/16" rings;
4-bolt main block;
Forged tufftrided crank;
7/16" rod bolt rods;
7/16" pushrods;
850 Holley and a dual plane intake w/ the divider cut down;
Aluminum rect port heads;
PN -180 solid lifter cam spec'd; 262/273, 110/?, .556"/.594" and need's .024" and .026" lash.

This will get you in the ballpark if you are serious about wanting more info.

The bad thing about this MONSTER is that it needs GOOD GAS due to it's extremely high compression ratio. I figure it would be a great E85 gasohol engine if carbed right!!

I bet that you can probably still buy a new NOS crate LS-7 engine if you hunt around, even today!!

pdq67

does anyone have good history or specs for the awesome ls7??thanks,jim

I had a chance to buy one when I place an order for an LS6 454 several years ago. The dealer had ordered if for a customer and the customer bailed out. I was offered a deal that was interesting but I went with the LS6.

Specs. The crank was a step up from the LS6...better grade of forged steel, more compression as mentioned above, same heads as the LS6. The LS7 that was at my dealer had no intake manifold and I was told that all of the LS7 motors were delievered W/O intakes. If I recall there was no flywheel, like my LS6 had, likely that covers the differences. Oh yeah the cam was much more aggressive than the LS6.

All the LS7 motors were built using the generation 1 BBC blocks.

Mark IV blocks!!

pdq67

i have got a guy who claims he rebuilt an ls7 with 10.5 keith black pistons and supposedly will put out 600+ horses with a carb and distributor??also it does have xch code and iron heads??does this sound fishy or legit>>thanks,jim

i have got a guy who claims he rebuilt an ls7 with 10.5 keith black pistons and supposedly will put out 600+ horses with a carb and distributor??also it does have xch code and iron heads??does this sound fishy or legit>>thanks,jim

fishy. :yes:

Back in the mid 70s a very good buddy & neighbour had a 69 vette with an over-the-counter LS-7 in it (him & I were the only vette guys in town) . He ran it on 1/2 av fuel & 1/2 high test. With this set-up, 850 Holley GM alum high intake, 4.10 gears 4sp & 28" Racemaster cheater slicks he ran an 11.87 on a local track (80 miles away:p) thru the side exhaust & take my word for it he wasn't the best 4sp guy around :D Sure wish I could remember the MPH :sad:

Some of you guys do the math with weight of a 69 BB vette, & I'm not even gonna guess what was in it with better driver, tires & practice. He only ever ran it on the track that one time & only had two track runs with no practice.

The thing I remember most is the pop out the exhaust when idleing...& trying to lean ahead on accell...awesome car..awsome stock motor..:yes:

The LS7 was basically the 454 cast iron head version of the 427 L88. See the following thread. I posted a pic of the heavy duty parts list for the LS6 and LS7 crate engines.

http://www.chevelles.com/forums/showthread.php?t=168757

Late 80's, early 90's GM sold LS6 and LS7 crate engines. The part number for the LS7 was 3965774 and has an engine suffix of XCH. It has open chamber cast iron heads, part number 6260482.

http://i82.photobucket.com/albums/j275/killerchevelle/LS-7STATS.jpg

Sorry, I got the head material right out of that old book.

pdq67

The bad thing about this MONSTER is that it needs GOOD GAS due to it's extremely high compression ratio. I figure it would be a great E85 gasohol engine if carbed right!!

pdq67

This is what I plan on doing with mine.

In addition to all of the above, I have a good friend who bought TWO of the LS7 crate engines and had them around for several years. About two years ago, I posted right here that he had both of them for sale. NO TAKERS! So, he sold them on Ebay. Both were still crated and both had iron heads.