All of you have to understand that the intake and heads have to work as one unit to get the benefits of the tuned intake port. Strapping a big port single plane onto a small cc head port defeats the purpose unless the head is then port matched to the intake. The worst case would be installing small port dual plane on big cc intake port heads. You get fuel sepparation and ..........................

I build 3.875 396 ci stroker motors and they are much more powerful than 3.750 383 ci strokers. The 4 inch stroker 408 would get you into the 11.'s even easier.

Have they told you which Dart Pro1 heads they are using?

 

Put a 170 runner head and a rpm dual plane on your 408 that way
your engine will be plugged up for breathing both at the heads then
at the manifold. or you can use a 190/200 head and let the good
airflow head breath for the 408 and then plug it off with a dual plane
manifold. or you can run a 190/200 heads a victor jr then plug off the
airflow with a nice 650 carb thats a nice torque carb for 350s.
460 torque 2000 rpm board flat torque to 510 hits 550 hp by 6000
rpm, has 215 runner victor jr heads victor jr manifold. mans hurting
bigtime for torque with the 3500/8000 rpm victor jr manifold.
If I had **** poor air flow factory 400 pontiac heads I would not
bother putting a manifold that can flow air on them I would use
a torquer or dual plane the heads don't flow anyway.

 

I don't know about other single plane manifolds only the Vic. Jr. I also know about the RPM Air Gap. Here's the deal, I have run them both on the same warmed over 355ci on a chassis dyno. The Vic Jr. gives you a few extra ponies up top with no low end power loss over the Air Gap. I repeat no low end loss of torque over the Air Gap and this was on a little 355ci, you would probably pick up torque with Vic. Jr on a bigger motor over the Air Gap as well as more peak HP.

Like gkull says, parts have to matched and if so this loss of low end power myth with a single plane is another old wives tale like Holley 750DP's being too big for a 355ci, 406's overheating etc. etc. Because of these myths that keep getting regurgitated all time, some engine builders I would think, probably put a dual plane on motors they want to sell to keep people that believe these myths happy.

We are not talking big power changes here but the Vic Jr makes you a few more ponies over the Air Gap so why wouldn't you put one on ?

Besides the Vic Jr looks

 

I have bracket-raced my 355CID-powered Z28 with both a Victor Jr., and an early-'60s 327/365HP dual-plane intake with the same #4779 Holley, and the only variation in ET (less-than a tenth? ) is probably due more to weather-factors and track-prep than anything-else:
of-course, having a very-loose converter and 4.11s may effect the overall HP/TQ out-put and consistency of the car, and the more-knowledgeable members of this Forum can debate that better than I.

 

Gskull, the Dart Pro 1s are the ones with the 2.08 intake valves. Thats all I know, they are right out of the box. Not sure what the flow in them are, probably 250-260cfm at .550 lift or so.


Motorhead, Victors do look pimp but...I am going to paint my entire engine orange and put factory orange valve covers on it and the air gap intake is SLIGHTLY easier to pass off as a stock type intake compared to a Victor. LOL THere is also an air gap that is port matched to a felpro 1205 gasket you can buy already ported. I will talk to the builder when it gets that close to time.


Little Mouse, are you unleashing the violence? Do we need counseling?

Ya pontiac heads SUCK. but believe it or not, the torker II intake on a pontiac will make substantially more power across the board then any other intake on any 400-455". MANY tests have been done on pontiacs with the torker II. In recent years, they have come out with a Victor for pontiacs but its more for big inch, high rpm motors. That sucker is freakin tall, almost like the old Team Gs for BBCs. WAY too big for anything that only spins to 5500-6000k rpms.

Damn maybe I should start a manifold thread.

 

Also using a victor Jr here on my 383 got tons of low end torque i can burn my tires to the ground from idle if i want to.

Actually the victor jr intake's runner size are smaller than my heads 227 (brodix track1 cnc) you guys say this is a problem, please enlighten me.

 

Great heads. I started up my first 383 with Dart Pro1 215 cc with the optional 2.08/1.625 valves. The only problem is that the ports are 1206 FelPro gasket size and require the bigger single plane intakes.

The smaller 200 cc heads with 1205 gaskets don't have the 2.08 valve option.

http://www.dartheads.com/manager/upl...PRO1%20SBC.pdf

 

You know maybe they are 2.05, I could have sworn LLoyd told me 2.08s. Tomorrow I am calling T&L for a full written quote with part numbers and specs. Then I will know for sure everything going in here.

You guys think if the crank and rods are not big brands like Eagle or Scat I should stay away from this motor? I mean they have to be getting a price break on something to be able to sell this engine this cheap. I pieced it together buying the parts from Summit and I can BARELY match $4800 and thats no machining, labor, tuning or anything.

Its a hell of a deal but...you know how that sometimes goes... Get what you pay for...

 

Your big engine shop can cut out the middle men. Or they are given Jobber prices. Labor is a big thing to you and I because around here a shop rate might be $80 per hour. But the employee is only getting $30.00 with insurance benifits and SIS and Social Sec. tax. So these shops are able to do all the labor much cheaper than we can get it done.

Some of the engine shops out of California have lots of illegals being paid less than $12 per hour to mass assemble crate motors.

If it has a warranty and it's internally balanced go for it. Stroker motors have so much power compared to hot rodded 350 ci. It's the TQ!

 

I would stay away from non name brand cranks and rods, you know they are Chinese and the problem there is while Eagle and Scat use Chinese steel they are machined in the US and go through quality control in the US.

You are taking your chances on a brand X forged crank IMHO, the machining may be perfect but a defect in the steel might or will show up at 6000RPM

A way they save is: Does it say the parts are brand new ? The crank could be turned 10/10 and the rods reconditioned, not that there is any thing wrong with a 4340 Eagle crank that is turned 10/10 but did it come out of a 8000RPM small block race motor that had 250 passes on it ? You don't know and if it did, I wouldn't want it in my motor

 

I don't care what manifold you run it will not really affect me, I would
like to see you run the best combo of parts. a 3500/8000 victor Jr
becomes a 2000/6500 manifold on a 408. the 1500/6500 rpm dual
plane will be lucky to be the 5500 rpm performer on a 408 size engine.
but you do not have to believe a word I say, every time you see a
400 tested with a hydraulic roller you see a single plane victor JR.
rpm ratings on small block chevy manifolds are just like cams based on a 350 size engine.

 

Interesting never really looked at it that way but sure explains why the Vic Jr. seems to work good at lower RPM's for my 406ci

 

My guess would be the forged crank is Scat, when Lloyd built my 383 he preferred Scat over Eagle, mine is 9000 series cast though. Your research on parts costs vs. Lloyd building is consistent with what I determined too, and I knew after I visited his facility and talked to him, it was a no brainer, at the time the dyno run alone was costing $500 at Goynes Engine(spelling?).

 

The heads on my 408 are the 215's with the 2.08 intake valves. now I am curious as to why Loyd recommended the air gap rpm over the Victor Jr. Think I will call him and ask

 

I will be contacting Lloyd today also to get a full written quote, parts rundown on the 408. I am trying to get the funds together now. I know it takes 6-8 wks for them to build the motor so.... I am hoping to penny up by Feb.

 

You might also want to check on the time frame. They were so busy when I had mine built that it took about 10 weeks. You don't want to rush your engine builder.

 

Yes, what I meant was the hyd roller cam upgrade. The duration at 50 degrees on the intake is 230 and the same thing on the exhaust. 512 lift on the intake and the exhaust and it is on 108 lobe centers. I did some reading here on the forum and figured the air gap wouldn' t fit under my stock hood. I figured if I ever got around to getting a taller hood, I'd get the air gap.

 

It took about 12 weeks for me. I also spoke with Lloyd on several occasions, and he does not like to rush anything and screw it up. I didn't have any problems with them.

 

Craig, how many miles have you put on your motor? do you run it hard?

I am breakin my **** in and then its going to the strip ASAP. I figure the rear end or half shafts will be the next thing blow.

I am gonna have the th400 rebuilt at the same time along with all new 3" exhaust. Gonna cost some jack, thats for sure.

This bitch better run 11s. LOL

 

I talked to Loyd about intakes this morning, RPM Airgap vs. Victor Jr. Loyd said that for street ( under 6000 rpm )use the Vic Jr. will make a few more ponies on top but considerably less at 2000 RPM therefore he recommends the RPM airgap for street engines. If he builds engines for the strip running higher RPM's or motors over 550 HP then he uses the Vic Jr. Loyd said they have lots of hrs on the dyno to back this up.
It looks like I have the same build as CraigT79 except his cam lift is a little higher but I still make a few more ponies than he does so the RPM airgap must flow better than the performer.
BTW, Allen I don't know if all his builds use this but mine has the 1 piece rear main seal.