I've decided to put a 331 in my car and have a question.

68EFIvert · Aug 29, 2009

I am running a 306 right now and decided to go with a 331. I have purchased some H beam Scat rods and a Scat Forged crank. I plan on getting some -14 cc dished Probe Pistons. I have picked up a Trick Flow stage 1 cam to replace my E303 I have now. I plan on reusing my AFR 165 heads and 1.7 roller rockers. The only way I may step up to AFR 185's is if I sell my existing motor as a long block than a short block. I hope to have 475-500 rwhp when it is all done.

I am tempted to run a stock roller block since I can pick one up that is already bored and machined for $100. I hear horror stories about blocks cracking when you approach 500 hp at the crank. I hope to be well beyond that mark. I don't plan on spinning the car past 6000-6500 rpm. Is there much to worry about? Do I really need an aftermarket block for a street car? Thanks for the help.

stonecoldtx · Aug 29, 2009

68EFIvert said:
I am running a 306 right now and decided to go with a 331. I have purchased some H beam Scat rods and a Scat Forged crank. I plan on getting some -14 cc dished Probe Pistons. I have picked up a Trick Flow stage 1 cam to replace my E303 I have now. I plan on reusing my AFR 165 heads and 1.7 roller rockers. The only way I may step up to AFR 185's is if I sell my existing motor as a long block than a short block. I hope to have 475-500 rwhp when it is all done.

I am tempted to run a stock roller block since I can pick one up that is already bored and machined for $100. I hear horror stories about blocks cracking when you approach 500 hp at the crank. I hope to be well beyond that mark. I don't plan on spinning the car past 6000-6500 rpm. Is there much to worry about? Do I really need an aftermarket block for a street car? Thanks for the help.

I wouldn't recommend trying to put that power level through a stock roller block, you're just asking for it to split. Seen too many people report that this has happened to them above 450HP at the crank.

As to a 331 producing that kind of power, you certainly won't get to that level without some serious cylinder heads and a camshaft with a LOT more "oomph" than a TFS Stage 1--unless, of course, you plan to achieve that power level using this combo and a power adder, like Nitrous or a blower/turbo setup.

Maybe a better option would be to build up a strong 351, or even a 351-based stroker; I've heard that the stock 351 block will withstand up to 600-650HP with no problems, and I've seen plenty of strokers putting out that much in stock blocks.

dodgestang · Aug 29, 2009

stonecoldtx said:
As to a 331 producing that kind of power, you certainly won't get to that level without some serious cylinder heads and a camshaft with a LOT more "oomph" than a TFS Stage 1--unless, of course, you plan to achieve that power level using this combo and a power adder, like Nitrous or a blower/turbo setup.

Stone: He already runs an EFI setup with a blower.

Moving from the 302 to a 331 you are asking to pick up another 100 RWHP with 29 more cubes and cam change (to put it another way you are looking for a 25% increase in total usable output). I don't think the 165s will support it but I am far from the expert. Are you planning on changing pulleys to run more boost?

stonecoldtx · Aug 29, 2009

dodgestang said:
Stone: He already runs an EFI setup with a blower.

Oops! Sorry, Missed that part!

Heck, there's really no need to increase cubes then--just a stronger block and more boost!

65ShelbyClone · Aug 29, 2009

I bet a good cam and a little more boost could get you close to 475rwhp with the parts you have. Well, depending on how much boost you're running now. AFR 185s on the current shortblock would take less boost to hit your goal. A turbo would likely make ~50hp more at the same boost level, just as an FYI.

Personally, I wouldn't build a blown stroker around a stock block. There isn't anything that can be done to make one truly reliable above 500bhp. Some people have claimed over 600rwhp on them, but they always split shortly thereafter. When they do, there is a good chance it will take the rotating assembly with it.

68EFIvert · Aug 29, 2009

It looks like I need to save a bit more money for a block. My current setup was only ran up to 5200 rpm with a vacuum leak on the intake. My tuner feels I am likely at 430 rwhp with a little more rpm and the leak fixed. If anyone hears of a good deal on a good R/A block, boss, dart or man of war let me know. Since I am going this far I will likely sell my engine as a long block and take the extra cash and get some bigger heads.

blown65 · Aug 29, 2009

I myself wouldn't run 165's with a blower. N/A they would probably be ok, but you would be leaving quite a bit on the table with a power adder IMO.

There have been a few used blocks on nmradigital.com in the forums. You might wanna check there.

stonecoldtx · Aug 29, 2009

I wouldn't be surprised to find one or two on The Corral, either . . .

68EFIvert · Aug 29, 2009

I normally keep an eye on the corral. In fact I picked up my rods and cam from there. I'll have to check out nmradigital.com. Thanks!

68EFIvert · Sep 13, 2009

We'll I am still waiting for a good deal on a block but have another question. Since I am going for an aftermarket 4 bolt main block do I need to have a main girdle or is ok with the 4 bolt main caps alone?

rbohm · Sep 13, 2009

you dont need a main girdle with an after market block.

65ShelbyClone · Sep 13, 2009

Main girdles are for stabilizing "flimsy" 2-bolt main caps. The extra two bolts in 4-bolt main blocks already do that job.

68EFIvert · Sep 13, 2009

Thanks for the confirmation on the main girdle. I thought it was not needed but I just wanted to verify. I have a guy on corral that will sell me a new Boss block for $1350 plus shipping. I guess shipping will be about $100-150. If it is then I will step up and get it. It seems like used blocks are kind of hard to locate. Maybe if I waited a month or two for the end or race season more will come up. I think I will also place a want add on criagslist locally to see if something is close by.

68EFIvert · Oct 7, 2009

Still no luck on finding a block. What do you guys think of an original Boss block or a Mexican block. Are they strong enough to handle 600 HP?

68GT500KR_Vert · Oct 7, 2009

Go BBF! Drop a 460 in there and have fun!

68EFIvert · Oct 7, 2009

Why go with a heavy big block when I can make more power with a small block?

68GT500KR_Vert · Oct 8, 2009

Weight different isn't that much and even a mild BBF puts out 550HP. It will bolt right up to your trans.

it's about 150lbs more than a 302 BOSS block if you use aluminum heads, intake, and water pump.

classic boost · Oct 8, 2009

blown65 said:
I myself wouldn't run 165's with a blower.

i made 500rwhp with those heads and turbos (stock cam & pump gas, too). they're an efficient head.
68efivert, check out the new dart 'shp' blocks.

68EFIvert · Oct 8, 2009

classic boost said:
i made 500rwhp with those heads and turbos (stock cam & pump gas, too). they're an efficient head.
68efivert, check out the new dart 'shp' blocks.

I agree on the heads. There really isn't that much flow difference between 165's and 185's up to the lift of the cam I am using (trick flow stage 1). I figure that if I can use these heads with the good enough idea I can spend a bit more on the block. I have been looking at the SHP block and have been given a quote of $1599 shipped to me then tax on top of that since the supplier is in state. I had a quote from a guy to sell me a new boss block for $1350 plus shipping but no tax.

Does anyone know if the machine work for the blocks is about the same or would it run quite a bit more with one of them? I've also heard that the Boss block will require a special pickup ($80) and special oi; pump that adds to the cost.

So right now I am leaning toward keeping my 165's and getting a Dart SHP block but obviously am open to input from someone with more experience. Thanks!

js66coupe · Oct 8, 2009

Couldn't you do a partial fill on a stock block to strengthen it?

I've decided to put a 331 in my car and have a question.

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