Ls7 block or resleeved ls2 for a 427
11-30-2009, 01:43 PM
#2
If you're doing a mild 427ci build, the LS7 block is all you need. Resleeved LS2's are good for well over 1,000 RWHP.
The stock radiator and cooling system is also all you need. Just put a 160 t-stat in there and have your tuner program your fans to come on sooner when you get the engine in and do the dyno tune on it.
My stock cooling system and my 427ci down here in HOT south Florida runs cool as a cucumber no matter what I'm doing. A/C blasting, in traffic on a 90* day...no problem at all. Its all about having a clean condensor and radiator and a healthy, properly functioning cooling system.
Absolutely no need for aftermarket stuff for a mild N/A build.
.
The stock radiator and cooling system is also all you need. Just put a 160 t-stat in there and have your tuner program your fans to come on sooner when you get the engine in and do the dyno tune on it.
My stock cooling system and my 427ci down here in HOT south Florida runs cool as a cucumber no matter what I'm doing. A/C blasting, in traffic on a 90* day...no problem at all. Its all about having a clean condensor and radiator and a healthy, properly functioning cooling system.
Absolutely no need for aftermarket stuff for a mild N/A build.
.
11-30-2009, 04:07 PM
#4
How much is a bare LS7 block from GM, it comes ready to go right, just start assembling?
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11-30-2009, 07:18 PM
#5
Cost of the LS7 before shipping is $2724 the cheapest I've seen, that's only a couple hundred off the cost of the sleeved LS2, we incorporate all that into the build though. No we don't go with a factory hone job on he LS7, it get's cleaned up to our specs.
11-30-2009, 07:31 PM
#6
Thanks for the info, really for my application the extra strength of the sleeves is not going to make a difference. What is the reliability like on the sleeved motors. The price doesn't seem to be much of an issue with the qoutes that I have recieved so far.
Last edited by Orange Juice; 11-30-2009 at 07:37 PM.
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11-30-2009, 08:32 PM
#9
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If you have an LS1 now, you could consider adding Darton MID sleeves into it and getting to 427 or more. The MID sleeve will be stronger than either the dry sleeve LS2 or LS7 blocks as well. On top, everything you now have, sensors, harness etc will fit with no mods. Cost for MID sleeve operation looks to be around $3K - about the same as the other 2 options as well.
If you build the LS1, tell folks you just have a H/C/I engine and let them try to figure out why it runs so well.
Were you considering L92 or LS7 heads?
If you build the LS1, tell folks you just have a H/C/I engine and let them try to figure out why it runs so well.
Were you considering L92 or LS7 heads?
12-01-2009, 06:59 AM
#12
What I had thought would work is a 427 rotating assembly with cathedral port heads so that I could use my intake and injectors. I live in southern Ontario and would be willing to take the car anywhere from NY to Michigan but can't seem to get the answers from the builders that I have spoken to so far.
12-01-2009, 07:00 AM
#13
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There's a guy close to me who buys GM blocks, heads, etc. by the train car load. PM me, I'll give you his info, he has LS7 blocks and heads for a good bit less than GMPP...
12-01-2009, 12:51 PM
#14
FI and nitrous. Other reasons would be sleeve material. The LS7 uses a different sleeve material and we've seen some cylinder cracking issues with detonation (its also unsupported at the top). SO for my money I go with the sleeved LS2, even if the LS7 block was $2500 I'd still use the sleeved LS2.
12-01-2009, 12:54 PM
#15
What I had thought would work is a 427 rotating assembly with cathedral port heads so that I could use my intake and injectors. I live in southern Ontario and would be willing to take the car anywhere from NY to Michigan but can't seem to get the answers from the builders that I have spoken to so far.
12-02-2009, 06:16 PM
#17
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What I had thought would work is a 427 rotating assembly with cathedral port heads so that I could use my intake and injectors. I live in southern Ontario and would be willing to take the car anywhere from NY to Michigan but can't seem to get the answers from the builders that I have spoken to so far.
TFS 225 and a small cam, 92mm Ported Fast, 525rwhp and 571rwtq, sure is great on the street, it does good at the track too!!
12-02-2009, 07:11 PM
#18
Just had a LS3 427 put together for a hair over $4k Callies 4.1" crank, compstar rods and manley pistons. I also plan on spraying up to a 200 shot on the car. Ha if I blow it up I'll sleeve the block and make it a 440
Plenty of people running this setup with no issues and it might be "undesirable" but its easier on my wallet.
Plenty of people running this setup with no issues and it might be "undesirable" but its easier on my wallet. 
12-03-2009, 01:55 AM
#20
Show me a better price. That was TSP's website and I know SDPC is very close. Not to many places with better pricing unless they have a few blocks left over that they haven't sold or used for a while ( and I haven't seen them anywhere).
They used to be $2500 or so but GM raised the price and between TSP and US and HKE and SDPC and few others we go through a lot of blocks
They used to be $2500 or so but GM raised the price and between TSP and US and HKE and SDPC and few others we go through a lot of blocks