Trick flow 270s or 240s on a 383?

-
D

David Royce

Member
Joined
Mar 9, 2019
Messages
10
Reaction score
15
Location
Captain Cook, Hi.
I currently race a 383 and now my third "906" head has developed a crack. I am thinking about getting a set of Trick flows. The engine is .060 over which makes it a 394 cu in. The bore is 4.31" which is smaller than the minimum bore recommended by Trick flow (4.32"). The engine has 12.5-1 Trw pistons, a Hughes .587/.602 lift 290/296 duration solid lifter cam, and an M-1 single plane intake. According to the internet a ported "906" head with bigger valves might flow in the 280 cfm range. My heads were home ported and I don't know the flow and probably flow less. I see that a 6.4L Hemi Apache head flows 339 cfm at .600" lift while the 270s flow 343 cfm at .600". So I am leaning to the 270s. I am worried the 270s might be to big and be lazy at low rpms. Anybody have any recommendations?
 
Last edited:
Look up member AndyF and search his posts on his B engine build up with the truck flows.

He will also echo my suggestion and I’ll say use the 240 as the 270 is a max wedge port. AKA, too much/big. With limited intake selections.
 
270 is too much head for a 383. The 240 would require a potent short block to take full advantage of the port.
specs of the rest of your combo would be nice.
 
Andy F or IQ 52 will hopefully chime in. I believe Jim ( IQ 52 ) actually did some valve lift interference tests with the 240's on a 383.
 
fishmens67 said:
270 is too much head for a 383. The 240 would require a potent short block to take full advantage of the port.
specs of the rest of your combo would be nice.
Click to expand...
Thank you for your reply, I have a 750 double pumper, a 5000 stall converter in a two speed powerglide transmission, and a 4.30 rear axle. I race 1/4 mile and only have one track here on the Island. Let me know if you need any more info on the car.
 
Thinking about the cam e size min. requirements as listed by TF, if there was an issue, I’d bet a small block trick would do the trick, “Bore Notch.” 360 heads on a 273 combo is illustrated in the MP books. The same idea could be executed on the 383.
 
I was thinking of the 240’s for a new 383 (30 over) for my car.....This thread leads me to believe the 240s won’t work on a 30 over 383… Is that correct?
 
The OP notes a .010 interference via TF recommended min. bore useage.

Hence my small block trick mention where you can notch the bore of a 273 to fit a larger 1.88 valve from a 360 head.
 
TF heads, as nice as they are, probably wouldn’t be my choice for a 383 with a mid-sized cam a two speed trans.
But $$ per cfm, they’re a bargain and hard to ignore.
I hope you do it, since I wouldn’t....... and I’d like to see how it turns out.

I can do my own head work, so my view on what to use is different than someone who is paying to have work done.

I’m not sure the trw 383 dome will clear the TF chamber without some trimming(it might, it might not).

Also, it’s very rare that a home ported 906 would flow 280.
Typically more like 240-260, with flow dropping off above .500-ish.

This is another one of those things that would make for an interesting test.
Ported 906’s vs TF240 vs TF270 vs ?? .........On a stock stoke 383.
 
Last edited:
PRH said:
TF heads, as nice as they are, probably wouldn’t be my choice for a 383 with a mid-sized cam a two speed trans.
But $$ per cfm, they’re a bargain and hard to ignore.
I hope you do it, since I wouldn’t....... and I’d like to see how it turns out.

I can do my own head work, so my view on what to use is different than someone who is paying to have work done.

I’m not sure the trw 383 dome will clear the TF chamber without some trimming(it might, it might not).

Also, it’s very rare that a home ported 906 would flow 280.
Typically more like 240-260, with flow dropping off above .500-ish.

This is another one of those things that would make for an interesting test.
Ported 906’s vs TF240 vs TF270 vs ?? .........On a stock stoke 383.
Click to expand...
Thank you for your response, I didn't think my home porting would flow that much either. That was a flow number I found online for a 906 head. Still hoping to hear from AndyF on what he thinks about it. The only reason I thought about the 270s was about the 6.4 Hemis and the Apache head flowing 339 cfm.
 
My .02 on that is.......

Trying to compare a modern hemi style head, that’s used with computerized engine management and vvt, vs an old school wedge head with a carb, and trying to base which head to use on that old school wedge combo by comparing/matching flow numbers between the two will lead you down the wrong path.....IMO.
 
I agree. That’s not the best comparison. But I get the thoughts behind it. There two totally different shape size length ports.

If you can fit the 240’s on the 383, even if a bore notch is required, go for it. That is going to be plenty of head for that engine.

Food for thought, small block guys can run 9’s with less head. (And cubes) OK, it is more of a race car, but not a full tilt one & as well as lighter, but the power can be made.
 
Summit has Edelbrock E Streets for $1,150 a pair plus I have a 10% off coupon....that is $200 less than Stealth heads after prepping them for a 550 lift cam.... should be fine for a 30 over 383....
 
E4F7C4A3-FE9B-4B78-9793-CB511A12C56C.png
rumblefish360 said:
I agree. That’s not the best comparison. But I get the thoughts behind it. There two totally different shape size length ports.

If you can fit the 240’s on the 383, even if a bore notch is required, go for it. That is going to be plenty of head for that engine.

Food for thought, small block guys can run 9’s with less head. (And cubes) OK, it is more of a race car, but not a full tilt one & as well as lighter, but the power can be made.
Click to expand...
I have this engine in a 1981 Dodge Omni. (Sorry not an A body). It ran a best of 10.29 ET. My Omni is in the far lane. In the near lane is my son’s 1968 Dart. The Dart has a 541 with Indy ported 440-1. It runs 9.3 in the quarter mile.
 
Thank you everyone that has responded. I guess what it comes down to is what is the head flow requirements of a 394 cu in engine in the 7000 rpm range? There is probably a formula for that but I don't know what it is but maybe someone else does?
 
What kind of power are you looking to make?
 
I don’t see why not.

There’s a thread over on speedtalk right now about hopping up a 383 sbc that’s being touted as a real underachiever....... and it was making 560hp.
 
Would the CNC stealth heads that 440Source offers be a viable option for this 383?
 
Ottmundr said:
Would the CNC stealth heads that 440Source offers be a viable option for this 383?
Click to expand...

Not a step in the right direction vs the TF240 IMO.
The Stealth has a 252cc intake runner vs 240cc for the TF, less flow vs the TF, and the TF’s are cheaper(and come with nicer parts).
At 394ci, it doesn’t need a bigger port that flows less.
 
If it helps I was in the same boat, .030 over 383, talked to Trick Flow and they said they wouldn't clear the cylinder bores. So I went with a set of Indy 440 ez. I'm on a budget so I got the cheapest ones, i.e. smallest port, which I think works well with the motor. Because, in my mind it helps keep port velocity up.
 
383Duster said:
Summit has Edelbrock E Streets for $1,150 a pair plus I have a 10% off coupon....that is $200 less than Stealth heads after prepping them for a 550 lift cam.... should be fine for a 30 over 383....
Click to expand...
Thank you for the reply, are you volunteering to let me use your 10% off coupon?
 
You must log in or register to reply here.
-

Back
Top