On the 350 vs 383 discussion item: yes, a good 350 can be built to have more torque than a "meh" 383.

When COST gets factored in, the larger CU IN motor seems to win, though.

I still think cost roughly coorelates to ft lbs / cubic inch and hp / cubic inch -as long as you stay within a typical range of cubic inches.


More ft lbs and hp per cubic inch USUALLY / very often comes from more RPM; to maintain reliability with more RPMs, requires more cubic dollars.



I think there's a couple of edge cases where you can get some good increases in ft lbs / cubic inch for a reasonable outlay in cost (also note: none of these options requires moving the power band into higher RPMs):

• A good, off-the-shelf tuned exhaust system that includes appropriately sized headers increases torque by a considerable amount for what you pay (There's not just "power in exhaust systems"; there's a lot, a LOT of extra power available from a good exhaust and for very reasonable money. There's a reason that there's so much secrecy surrounding pro racing exhaust systems and designers.) -Personally, I'd say go with a good scat 9000 cast crank if you're not going to spray and hp won't go over 500hp and put that money into the exhaust.
• A modern high-velocity, head designed to focus on min and average CSA -like the AFR, Profiler, or ProMaxx heads, can get you a huge jump in ft lbs / cubic inch (and HP) for not much more than a "CFM at all costs" old design made based solely upon airflow bench flow #s.
• A cam that's well-matched to your build/ goals with modern high-velocity lobes. Yes, there's a longevity trade-off, but modern springs are shockingly good and if ft lbs / $ are the goal, this can help.

Now if you've already got a perfectly good 350 and good heads, good exhaust, and a well-matched modern cam can get you to your hp and torque goals, then the extra ft lbs across the curve provided by the 383 and the extra $$$$ spent may be completely unnecessary. These discussions usually happen in some sort of theoretical world where the thread OP doesn't currently have a motor and is looking to decide "green field" between a 350 and a 383 (in which case I agree the 383 is probably the better option for the $$).

Adam

 

For a 383. But now you're talking about a 396.

 

on equal length ie tuned headers I would never do it again colossal waste of money...depending on the car it can make servicing the car a nightmare wish Id never bought them. buy what you can afford and fits youll never notice any power difference

 

Glad to hear that your heads were good and I'm sure all manufacturers get it right some times even with a production head. Mine were not and was rather disappointed with them as far as quality goes for the price paid. I did not contact AFR nor attempt to replace them because of time restraints with other machining and other issues that I would run into with the motor install etc... which would have been a domino effect. I also replaced the valves that came with the heads that were good to I believe .600 and went with a good LS spring set for the new cam I installed to ensure a little head room with lift on new Bullet Racing cam I'm running.


You are correct and I have provided three vids on that subject and AFR heads that were out of the box production heads. IMO, you MUST check any head that you receive before installing them to ensure they are correct as the manufacture says.

The vids were made by a friend of my machinists who is in CO. According to my machinist, he is very good and ONLY does AFR BBC heads from what I understand, don't ask me why, since I don't know, but would assume it has to do with tooling setup maybe? I'm NOT trying to beat up AFR here, just making people aware of possible issues wth new heads no matter who makes them. Happy viewing.

 

Two weeks ago I called Jegs for their Jegs/Profiler heads (72cc) and they had only one on stock, and no more coming... They told me that they are discontinuing small block heads?!
They proposed Dart Pro 1 as replacement.

 

I installed my AFR 195's from the box to the engine. Runs terrific, no issues and makes lots of power. I find it hard to believe that a 5-axis cnc machined head that AFR turns out would have tolerance issues. But, I guess it can happen. I would buy AFR again without hesitation just the same.

 

You could be correct, but the videos don't lie. They are AFR heads right out of the box and they are not properly machined from the manufacturer. Again, this is NOT to beat up AFR, but to make people aware of things before installing new heads. BTW, my ynew AFR heads work great and make good power.

 

Never seen the video. How many heads are they talking about?

 

Watch vids from #44 post above.

 

I checked, it seems summit has profiler heads in numerous sizes.....195cc 64cc 2:02 1:60 straight plug for 631 each....

 

Pro Maxx heads are from what I have seen fairly good heads. I would not bolt on a set of heads without taking them to an expert on engine building, so many things that can be bad and you have to match the springs to the cam, most likely not the springs the heads came with.

I always buy heads bare and fill them with the correct parts for any given engine.