70 LT1 Engine Questions
Thread Starter
Instructor
Joined: Feb 2005
Posts: 153
Likes: 1
From: Monroe MI
70 LT1 Engine Questions
I have a 70 LT1 engine I purchased I was going to put in my 68 but I have a few questions. The block is not original but heads and intake numbers match so I have a few concerns. Does anyone have a pic of what pistons should be in this? They are what 11:1 correct? The heads are the 492s and need some checking out just to be sure. Am I better off buying aftermarket heads or if these check out OK to just have a valve job done on them if thats all they need? For the rockers whats the big difference between the 1.5 and 1.6 ratio? The 1.6 will give more lift right? ID this really needed?
Chris
Chris
Drifting
Joined: Jan 2006
Posts: 1,944
Likes: 22
From: Yooperville MI
I rebuilt the LT-1 in my '70Z 9 years ago and spent around $300 on the heads for a 3 angle valve job, hardened exh. seats, and a mild port job, that's just machine shop work. In addition I bought new Manley stainless valves and assembled the heads myself. I went upside down pretty quickly with all the incidental parts, but they were original to the car and enhanced from the originals. In hindsight, I could have purchased a pair of World Products S/R heads for $600 at the time fully assembled and put the originals aside for when I sold the car. Painted orange, not very many people would notice the difference.
I your case, you aren't working on a matching engine for the car, so you are wide open for ideas. I would purchase new heads either cast or aluminum that breathe better and sell the ones you have. JMO.
I your case, you aren't working on a matching engine for the car, so you are wide open for ideas. I would purchase new heads either cast or aluminum that breathe better and sell the ones you have. JMO.
Drifting
Joined: Aug 2004
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Chris, just so I am clear, is it fair to say you do not have the original LT1 block? If so what block do you have?
Thread Starter
Instructor
Joined: Feb 2005
Posts: 153
Likes: 1
From: Monroe MI
Yes I do NOT have the original block, mine is a 1975 4 bolt truck block. This engine came out of a 1970 Camaro my brother had, I bought it from him and he'll probably end up buying it back now . . . Mien doesnt have LT1 Pistons or even OEM replacements. Looks like I have run of the mill flat tops with the 4 recessed slots for the valves. It looks like someone probably either blew it up at one time or something and rebuilt it with the original cam, heads, intake . . not sure about the lifters but he also has all the original brackets, pulleys and accessories. Either way I think I'll pass on this one but if someone else is interested let me know.
Chris
Chris
