#21  
Old 08-24-2021, 06:37 PM
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pontiacmark pontiacmark is offline
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Limited a little by 68404 springs, but yes, I could go bigger.

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1970 GTO 400 Atoll Blue, PS, PDB, A/C
Was M20 4 speed, now has Keisler RS600 5 speed.
  #22  
Old 08-24-2021, 10:18 PM
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pontiacmark pontiacmark is offline
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With the Crower 68404 springs I have installed, max lift would be about 0.520". The Crower 60244 specs: Dur @ .050” Lift: 239/241 RR: 1.5/1.5 Gross Lift: .500”/.500” LSA: 112
Now where to get?

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1970 GTO 400 Atoll Blue, PS, PDB, A/C
Was M20 4 speed, now has Keisler RS600 5 speed.
  #23  
Old 08-25-2021, 09:40 AM
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67Fbird 67Fbird is offline
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sounds very similar to the mighty mighty "041"......with 1.65 rockers. thats going to put you in the 450 hp 500 ft/lbs range idle-5200 rpm. Only thing you need after that would be a total top end swap of serious heads n cam to go 625 hp (all out of the box bolt on in the car stuff )

oh and $$$$$

  #24  
Old 08-25-2021, 02:01 PM
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TransAm 474 TransAm 474 is offline
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With a 4.25" stroke crankshaft and around 9.5 compression, I would look at the Lunati VooDoo 704 camshaft, if you can find one. We are building a 467(W72 400 with 4.250" stroke), and that is what we put in it, we haven't gotten it running yet, still awaiting our SMI Qjet, so I can't weigh in on the results just yet, but it was one of the top recommended here on the forum when I was researching it. Lots of good info on the threads that I started here, search for "W72 Stroker" and they should come up. Another good recommendation is the RA IV 041 camshaft, and some like to run Rhodes lifters on it for the best response and drivability. While the 041 camshaft would work good down around 9.5 compression, it would like closer to 10-1 even better probably, and still manage pump gas easily, as long as you build it with a nice tight quench(.035- .040") by having the block zero decked and using the Felpro 1016 .039" thick head gasket, which really should be done with any application, and keep total timing in the 30-34 area.

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1978 Trans Am
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