I have a set of 202 heads and block from a 1970 LT-1 Corvette. Thier genuine from my dads old vette. The block has a hairline crack so I was wondering if the heads will work on my 305 LB9 TPI? Actually. I suspect the extra flow of those heads will be hindered by the TPI's flow. Would it be worth it to swap them in or is it a waste of time? I have the cam too and it is in good shape. The old LT-1 was 11:1 comp and the LB9 is 9:1 so I suspect there would not be valve to piston clearance problems? Can any of you guru's enlighten me?

 

I don't think you can put 2,02 heads on a 305 the valves are to big and the bore is to small so the valves will hit the cylinder walls. but I could be wrong.

 

I can't remember if the 305 is the same bore with a shorter stroke or smaller bore with the same stroke. One of my buds put 350 heads on his old blazer's 305 but they were 1,84s

 

305 = 3.736" x 3.48"

350 = 4.000" x 3.48"

 

Not a good choice for a TPI 305.

The old LT-1 cam made very good power in the Hihg compression Z28 LT-1 motor.
A tpi motor is a low rpm "torque motor". The LT-1 cam does not match.
Would match a short runner EFI manifold much better, like the newer LT1 gen II EFI motor or a Stealth Ram uses. Needs lots of compression ratio, a 3000+ converter stall and a healthy rear gear ratio.
Why not find another 350 block to rebuild?

 

Not a good cam choice for a 305, EFI or not - its WAY too big. IIRC, the LT1 used the 'off-road' 302 Z28 cam, which was a monster. Something in the 240/250 degree @ .050 range. Thats the reason the LT1 cars with the TH400 had a 2400 stall converter installed at the factory, instead of the generic 1500 stall converter. Also how it got away with 11:1 compression too.

Plus, TPI doesn't take well to solid lifters - the mechanical noise drives it nuts.

 

Thanks for helping guys. I should have known the knock sensor and solid lifters wouldn't jive well. I'm gonna start hunting a shortblock 350 for those LT-1 parts.

 

check the # on those heads if they match you could make some good $ off them with someone looking for old school

i was like you 20 years ago--i got a 1970 1/2 lt1 350 from my father --still have the engine n heads but the car took out a tree and a cow---and all i got was a **** beating--and now a wasted dream of a car that I thought was just ok

 

Yes the #'s match! He bought the car new in 1970! In 1990 he got Bigtime rearended by a woman in a pickup while sitting at a stoplight. Pushed the vette into the crosstraffic. Not much left of the car except the motor. Put the motor into a 69' firebird. Started loosing coolant not too long after even though it ran good. He took it apart and found the crack. Then It just sat in under the basement stairs ever since. He died last year and it was left to me so I don't really want to sell it. I'm not sure if the original block can be fixed or not as I can't find where the crack is. He said it is screwed though. I'l have to bring it to a machine shop to get it magnafluxed. (I think thats what they call it.)
Sorry bout your old 70.5' camaro and the **** beating. I am positive I would have gotta legendary beating too if I was the one who wrote off my dad's ride LoL!

 

If its an authentic LT1 and has the Corvette codes on the block, SELL IT TO SOMEONE RESTORING A 1970 CORVETTE!!! These guys will pay unreal amounts of money for this kind of stuff, especially if its 'all there'. You could easily build a VERY stout 350 with NEW parts for the money that engine would bring, if its complete.

 

Find your self a 010 350 4 bolt block and put all the innards from your LT-1 in it.
Keep the old block for documentation/verification. (serial #)
If you an get a stock bore block with minimal cylinder wear all the better. ( Find a complete running motor with the right block casting number (1968-1980)
If the new block will take a hone without boring it (minimal wear) and the mains
saddles are round and straight all you need to do is hone and clean the new block and reinstall with all new bearings and rings.
Keep your eye on the original forged steel crank and rods and LT-1 heads. Do not let the shop substitute. I would mark them for ID. Some shops love to "substitute parts" for unknowning customers. These parts are rare and they know it.
In reassembled and freshened up form, including the old block, its worth big bucks. Don't even bother magging the old block. But keep it.
The connecting rod big end needs to be checked for size/round spec for proper bearing crush. If they are out of wack, resizeing is necessary or you will have bearing trouble. (nominal cost, but critical)
If the crank journals a re good just have it polished, other wise get it turned "10-10". Mark the crank for ID so you get the original back from your shop.

Note: If the cam and lifters show even the slightest wear, replace them.
You can buy a quality "Blueprinted" exact replacement from Crane Cams and/or GMPP for just over $100. Again, keep the old cam for documentation.
Not worth reinstalling a worn camshaft/lifters.
1970 350 LT-1's came with two different cams.
Early 1970 motors came with a .485"-.485" 254-254@.050 114LSA cam.
Later 1970 production LT-1 motors (and all 1971-1972 LT-1) came with the newer revised cam .459"-.485" 242-254@.050" 116LSA.
Measure the cam lobe lifts with a mic to verify your cam.
Blueprinted exact replacements are available for either version.
Inspect the heads carefully and replace the valve seals.

I would get in contact with a restoration shop like http://www.legendarymotorcar.com/
Before you start.
They may want to buy (or find you a buyer) the motor now or after you have repaired it, for a future restoration car.
These guys are the real deal.

 

That sounds like a great plan to me!!! Thank you very much. I really want to keep it for sentimental reasons as I remember riding in that car as a tot and a teenager. Either I will do what you said and throw it in my Z28 or find a 70's Vette with a good running 350 to swap it in like my dad wanted to do but never got the chance.
Sincerely Allan.

 

Yes I've seen the "legendary motor car" guys on speedchannel and they very much do look like the real deal. Thier cars are perfect. I for sure will have to contact someone with that skill and integrity level. Better to pay a little more for quality and assurance than to get bamboozled. I don't know of anyshops out here B.C that are either capable or honest enough. (I have some trust issues I need to deal with.)I just got this motor from the will recently so I haven't had much time yet to figure out how to go about things. I greatly appreciate your heads up and valuable info.