Need help...
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8th Gear
Joined: Apr 2011
Posts: 8
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From: Sandy Utah
Need help...
I picked up my dad's 74 vette that he bought as a project car but got teardown done and well that was about it, so I'm left with a 350 short block with 4 bolt main (assuming not original block, getting casting # from him today), and heads cast 3973487X (which I already know a little bit about, obviously not original heads). I'm seeing so many different options for what I can do with this car. With the heads being such a large head with a fairly low compression ratio would I be able to bore .060 over and run a dome piston with 2 relief valves and still be able to run on pump gas? In order to run a dome piston is there any more modification that needs to be done i.e. shorter rod for a slightly shorter stroke or can I run it with a stock rod? Also, can the crank handle the additional power? I am new to all of this and would appreciate any help. Thanks, Brandon
Thread Starter
8th Gear
Joined: Apr 2011
Posts: 8
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From: Sandy Utah
Also, have a comp cams XE268H-10 and springs, pushrods and rockers. The heads I have not measured but I am pretty sure they are the LT1 head since they have the screw in studs. (from what I've read). Will this cam work for my combination of the heads and dome piston to make a 360? Also any recommendations on where to find parts to do this would be great, not sure if summit racing sells anything of quality or not but their prices seem to be pretty reasonable, trying to keep this all on a budget since its my first build I don't need or want to overwhelm myself.
Race Director
Joined: Apr 2000
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Do the heads have 1.94/1.5 or 2.02/1.6 valves. They are also 75cc heads which doesn't help compression any. The X on the end indicates they are not LT1 heads.
What do you mean by big heads ? The heads in my sig are AFR 227 Eliminators, ~ 230cc intake runners, flow ~320cfm and have 2.10" intake valves, now they are big small block heads
What do you mean by big heads ? The heads in my sig are AFR 227 Eliminators, ~ 230cc intake runners, flow ~320cfm and have 2.10" intake valves, now they are big small block heads
Thread Starter
8th Gear
Joined: Apr 2011
Posts: 8
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From: Sandy Utah
Not trying to argue but I thought the difference in the LT1 head wasn't by the X but by the larger valve sizing and the screw in studs? I understand that having a 75cc chamber stock piston will keep compression probably around 8.5:1 ish, which is why I'm wondering if a dome piston could work to raise my compression but still run pump gas, and help with some added power, while also boring .060 over but keeping the stock stroke? I'm hoping to get around 400hp on the crank.
Race Director
Joined: Apr 2000
Posts: 17,672
Likes: 199
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Not trying to argue but I thought the difference in the LT1 head wasn't by the X but by the larger valve sizing and the screw in studs? I understand that having a 75cc chamber stock piston will keep compression probably around 8.5:1 ish, which is why I'm wondering if a dome piston could work to raise my compression but still run pump gas, and help with some added power, while also boring .060 over but keeping the stock stroke? I'm hoping to get around 400hp on the crank.
For $30 you can get one cylinder flowed at your local race shop and then that gives you an idea of what the rest of the parts should be.
Those are old heads, modern fast burn heads will leave those heads in the dust. They did manage to make 375hp with the LT1 but it had solid lifters and was one of a kind the rest of the small blocks were pretty pathetic by todays standards. I made 300RWHP with modern parts with a mild 355ci anyone could build.
