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This site is completely free and there are no costs. Please enjoy and provide feedback.Building a SBC with 700r4 and NP 241 left drop
- Thread starter kmakar
- Start date
So far, I found guys recommending the new Trick Flow double-humps in aluminum at $800 each as the best. https://www.trickflow.com/parts/tfs-30210006/make/chevrolet
The best budget head would be a stock vortec that you modify with better springs.
There's a guy on ebay that sells the stock heads and he will modify them with better springs for $60.
The trick flows do outflow the vortecs by 10% but I would bet the vortecs win under 3000 rpm.
The best budget head would be a stock vortec that you modify with better springs.
There's a guy on ebay that sells the stock heads and he will modify them with better springs for $60.
The trick flows do outflow the vortecs by 10% but I would bet the vortecs win under 3000 rpm.
The 327 is a great engine but a little short on torque for a truck that heavy. It may be taxing unless but the 700 has a pretty low 1st iirc. If that's what you got and that's what you're planning on running, I'd go flat tappet and a set of double humps IF you have them. If not, the vorteks are a great choice, and the ProMaxx 180s are even a better choice, but they've gotten a bit steeper in price than 5 years ago. They used to be well under $1000 assembled. If I was recommending a cam grind, I'd stick with 218-220 duration on a 112 centerline, and if it's a set of factory iron heads split that duration a bit more. I would avoid at all costs flat tappet cams off the shelf. There's a cam grinder local to me that grinds old cores for $100 to your specs and he's a wizard in profiling a cam to your needs. Lifters reground for another $100, and he grinds them right, which is not the typical case of typical lifters. Howards cam-saver lifters for a hydraulic is also a great choice, used them several times.
I remember now that promaxx was the budget head of choice. I found this and it looks a lot better value than the Trick Flow.
Fot the price, it's hard to beat this : it's setup for a hydraulic roller and has 185 cc intake ports
Promaxx are copies of AFR and from what Ive read very good heads, I wouldve went with them 4+ yrs ago over the Brodix but for whatever reason didnt, Straub is selling them
Im really wondering how much more power per dollar the new alum heads would be compared to Vortech heads? would it really be worth the extra $ ? Im not trying to be cheap but if it was my engine they'd need to be worth 30-40 min more hp, just my opinion and weight savings I really dont think is an issues in this build, or is it?
Bigger and more efficient pathways of air/fuel come into play at higher rpms......and become less important below 5500 or less. Those 185cc heads is what I picked for my 302 chevy, profiling it to shine above 4k and to 7000 rpm....they would be slide a bit lower on a 327, but really too big.
It's very hard to beat the 170 vortec for a street engine. It might give away a tiny bit up top, but it really shines making low end torque.
The only drawback is I would want to do the work on the valve springs myself. I cut down some vortec guides back in the late 90's and installed a small roller in a 350 chevy.
That was a really sweet running engine. It's hard to find someone to do things like this today.
Here's instructions for installing the new springs and screw in studs. Those Promaxx heads look better ? LOL
Here's a great video for screw-in studs
No machining for the valve lift mods ! Here's instructions with a parts list of springs, offset keepers, valve seals and seal installer :
Here's a great video for screw-in studs
No machining for the valve lift mods ! Here's instructions with a parts list of springs, offset keepers, valve seals and seal installer :
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kmakar
Janitor
I've decided I'll be using vortec heads, but they will be cast iron. I'll be breaking down the '65 327 to inspect it and then bring it in to have cleaned, bored, and trued. I figure this project will take a year to complete with everything else I'm working on. I'll have to locate a 700r4 and NP241 so they can be rebuilt as well (it'll be my first time rebuilding a transmission).
Cool. The vortecs will have better low end torque. This should be a really nice engine.
Torque is what Id be looking for in a truck engine 
I just read this from someone that purchased these heads, read the reviews
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kmakar
Janitor
Torque is what Id be looking for in a truck engine
While it is a truck, it'll be a passenger vehicle. Most likely will never tow and if it does, it'll be a small trailer. The 700r4 should help with 1st gear being low to help with the initial acceleration.
The TH400 has 2.48/1.48/1.00 ratios. The 700R4 comes with 3.06/1.63/1.00/0.70 ratios.
These are the rotating assemblies from the Scat catalog 
Couldn't resist because it's not much more $$ to go this way.
At least consider it. A 383 has 50+ more cubes so you will be up 60+ hp at every point of rpm. 400 hp is easy.
Vortec heads have 64cc chambers so the last rotating assembly listed (383 cubes) would have a 9.7 compression with 18cc dished pistons with 64cc chambers. Perfect.
383 stroker rotating assembly :
This is an externally balanced assembly that comes with a flexplate and damper, so that saves $300 right there ! It's $300 to balance an assembly these days
www.summitracing.com
Here are part numbers if you want to consider higher end kits
Couldn't resist because it's not much more $$ to go this way.At least consider it. A 383 has 50+ more cubes so you will be up 60+ hp at every point of rpm. 400 hp is easy.
Vortec heads have 64cc chambers so the last rotating assembly listed (383 cubes) would have a 9.7 compression with 18cc dished pistons with 64cc chambers. Perfect.
383 stroker rotating assembly :
This is an externally balanced assembly that comes with a flexplate and damper, so that saves $300 right there ! It's $300 to balance an assembly these days
SCAT Engine Components 1-92002BE Scat Engine Rotating Assemblies | Summit Racing
Free Shipping - Scat Engine Rotating Assemblies with qualifying orders of $109. Shop Engine Rotating Kits at Summit Racing.
Here are part numbers if you want to consider higher end kits
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Eagle has two affordable kits with forged cranks & pistons and one set has longer 6" rods
https://cnc-motorsports.com/engine-...ial=1391&piston_type=4275&rear_main_seal=4770
https://cnc-motorsports.com/engine-...ial=1391&piston_type=4275&rear_main_seal=4770
kmakar
Janitor
Relax Beth, I'm not there yet.
I'll consider it, but still leaning to keeping the block and 327 assembly and just boring it for now. I'm in the camp of KISS, and anything that pushes limits adds more complexity and more points of failure. This will not be a racing engine.
LOL, I'm not pushing you. You've been around me enough to know i like to shop for others.Relax Beth, I'm not there yet.
I'll consider it, but still leaning to keeping the block and 327 assembly and just boring it for now. I'm in the camp of KISS, and anything that pushes limits adds more complexity and more points of failure. This will not be a racing engine.
Lots of choices.