engine rebuild 1971 LT1

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Dec 12, 2014 | 12:40 PM

#21

Lt1er

Drifting

Joined: Dec 1999

Posts: 1,462

Likes: 1

From: Reno nevada

Quote:

Originally Posted by 63split63

Keep that LT1 in its origonal configuration. If it dosen't have enough power for you, you have the wrong car or it needs a good tune up .

Bill

Stock Lt1's were a real dog like the 390 hp 427s. Lots of room for improvement. I own or have owned them

Dec 12, 2014 | 01:16 PM

#22

63mako

Race Director

Joined: May 2005

Posts: 10,674

Likes: 122

From: Millington Illinois

St. Jude Donor '08-'09

Quote:

Originally Posted by LeMans Pete

Hey Mako,

Will those rockers and polylocks fit under the stock valve covers w/ the stock valve cover gasket?

Quote:

Originally Posted by NEVERL8

I have Comp Cams pro magnum full rollers. I use Felpro performance cork/lam valve cover gaskets, .301" thick. Works great.

http://www.summitracing.com/parts/FPP-1604/

Quote:

Originally Posted by Zimmo

I have Crane aluminum rollers under '70 LT-1 covers. I'm also using thick cork gaskets from Felpro

The Comp pro magnums have the smallest body of any of the roller rockers. The problem is always the polylock. I used the comp pro magnums under the midyear aluminum valve covers with turned down comp polylocks and they fit with no interference, had to shorten the set screws too. The short crower locks were not available then. It seems some say they won't fit and some say they do. I seen a Camaro forum guy that used the pro magnums with crower locks and stock covers and gasket and they fit, That is where I got the part numbers but can't find it now. They are really, really close. I know the roller tips will fit but I would want polylocks and full rollers on a solid roller. Might be able to change out the studs with ARP a hair shorter to gain additional clearance or drop the guide plates and use self aligning arms.

Dec 13, 2014 | 08:01 PM

#23

Solid LT1

Le Mans Master

Joined: Dec 2003

Posts: 5,727

Likes: 38

From: Fremont CA

Quote:

Originally Posted by MidShark

The '71 LT-1 that I had came from the factory with the 3.55 "economy" rear gear

. I had the engine pretty much rebuilt to stock specs with some mild porting, and it dynoed at 386HP. With the M-21, though, it was kind of a dog down low. At the track, it was not good out of the hole, and was a mid-14 second car at 99 mph (crossing the line in 3rd gear). A couple of years later I swapped in a 4.11 rear, and I couldn't believe the difference! It was so much quicker and fun to drive! I never took it to the track after that, but I'm certain that I could have gotten it into the 13's with no trouble. The point is that the LT-1 cam likes a lot of gear. I don't think I would have gained much going to a 3.70

WOW! way back in 1986 I bought my first C3 Vette a C-60 equipped 72 LT-1 with wide ratio M-20 and 3.55 rear gears, some major tuning on my part, I ran a 14.06@99MPH at Fremont Drag strip but, then again I spent the better part of my youth at that track. My 72 LT-1 had better than 96,000 miles on it at that time. The guy who had sold me the car to buy his " bitchen " 86 Vette came up and remarked, wow! I didn't know that car was that fast, my response back to him after spending the week with bloody knuckles and grunge all over, it wasn't that fast when you owned it, it was too neglected to run right, I spent over 14 hours bringing this Vette back into shape! Look on his face, PRICELESS!

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