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Old Jul 2, 2022 | 07:51 PM
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Default 427 ls3

Haven’t been on here in a long time as I have been waiting for my engine to be built.

long story short. I went cheap with a builder in Texas, (found out after all the **** work they do) who pretty much built a **** short block. Then had Hutter performance in Chagrin Ohio rebuild the short block again and take care of other issues. Can’t say Enough about what they did to help me out. Do a search on Thompson before spending money with them and save yourself the headache.

so after a year it hit the engine dyno and made 632hp NA and 590ftlbs at 6700rpm. This is a boost build and CR is at 10.00. custom grind cam etc. Planning on procharger this winter.

Been a long time but happy with results. Goal was procharged 850hp on pump 93.

In the mean time I bought a BMW Z4 M40i to placate my need for speed. It’s fast (much quicker than my stock GS) but does t have the soul my Vette does.
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Old Jul 3, 2022 | 08:43 AM
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Sorry to hear of your problems. Never dealt with Thompson, so no opinion, good, or bad. However, two words in your post really caught my eye. They are "went cheap." That said, I've had issues with big shops before. I've always felt they build two different type engines, depending on who you are. Magazine motors, and individual motors. Not all shops build like that, but I believe some do. One big shop I've dealt with has never disappointed. They are probably as expensive as any, maybe even more so. That shop is Lingenfelter. They charge a lot, but you get a lot. I hope your through the worst of it. Best of luck.......
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Old Jul 7, 2022 | 06:51 PM
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Agree. I should have gone with a reputable shop. Lesson learned. Should have car back in a week and plan to put some miles on it and then send it back for procharger.
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Old Jul 8, 2022 | 10:40 AM
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Thompson Motorsports of Texas? There are a bunch of really good and really bad reviews for them all over the internet, but you'll get that when somewhere is putting out hundreds of engines some will work great some will have issues. Sometimes shops that just push out big quantities of motors cut corners or do sub par work due to just trying to push stuff out as fast as possible.
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Old Jul 8, 2022 | 11:35 AM
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Didn't know that you could bore out a LS3 to 427 cubic inches, Interesting.
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Old Jul 8, 2022 | 11:44 AM
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Originally Posted by ls1121
Didn't know that you could bore out a LS3 to 427 cubic inches, Interesting.
The bore doesn't change you go from the stock stroke to 4.125" Stroke

3.065/3.075 bore with the following strokes give the CID
3.622 = 376/378
4" = 415/417
4.125= 427/429
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