I have a 1970 Duster with mini tubs. I have been waiting a long time to get to the engine build. I have been collecting parts for many tears and wish to use what I have to have a good street car. The target for me is in the neighborhood of 400 HP. So here is the set up. Automatic 727, 8 3/4 .373 gears. I plan to purchase a EFI kit which I haven't decided on. 1972 Cast iron "J" heads with 2.02 / 1.60), TTI headers with 2.5 exhaust, As for the engine, this is where I would like some guidance. Here is what I have: 1972 360 block, stock pistons, competition cam with the following markings (265DEH-10 YA5688), roller rockers. I also have 3 intake manifolds to choose from (Edelbrock performer 3776, Edelbrock LD340 or Weiand action plus). What combo and or changes would any of you guys that have been at this a long time make to achieve close to the 400 HP range? Your expertise would be greatly appreciated. I hope I covered all that is needed.
Engine Build For 1970 Duster
- Thread starter Dust Ya
- Start date
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Any port work on the heads? An honest and true 400HP will require some port and or bowl work on the heads. With as cast heads, you may see 350 - 375HP.
Heads are as cast. I got this engine years ago but disassembled it to understand what was in it.
j par
Well-hung Member
First and foremost when you're restoring an entire vehicle is to at least to get it on the road "keep it simple"..
The first thing I would do is ditch that EFI idea for now and just go with a simple carburetor... It will make things extremely time-consuming with a lot of work getting it all hooked up let alone the colossal expense... I've done a couple... Also did you know they don't recommend using EFI to break in a new cam with a brand new efi? When you break in a new cam you want to get it up to two grand plus RPMs right away and with an EFI you have to get it all tuned in itself and then hold a high rpm.... I called Holly sniper on this one and I believe it says it in the book as well to use a carburetor break in the cam if using EFI for the first time..
Second you tore down the engine to see what you have and if you cannot get the exact specs on that cam which I highly suspect you can't from those numbers on the end but you'd think you would. I would go ahead and either send that cam in to be reground to expect that you know and want or ditch it all together and get one that you know and want thing that was the reason you took the engine apart. To see what you had?..
My-2...
The first thing I would do is ditch that EFI idea for now and just go with a simple carburetor... It will make things extremely time-consuming with a lot of work getting it all hooked up let alone the colossal expense... I've done a couple... Also did you know they don't recommend using EFI to break in a new cam with a brand new efi? When you break in a new cam you want to get it up to two grand plus RPMs right away and with an EFI you have to get it all tuned in itself and then hold a high rpm.... I called Holly sniper on this one and I believe it says it in the book as well to use a carburetor break in the cam if using EFI for the first time..
Second you tore down the engine to see what you have and if you cannot get the exact specs on that cam which I highly suspect you can't from those numbers on the end but you'd think you would. I would go ahead and either send that cam in to be reground to expect that you know and want or ditch it all together and get one that you know and want thing that was the reason you took the engine apart. To see what you had?..
My-2...
From Comp Cams Cat...................
Comp Cams 265DEH, Very strong mid range. Everyday performance for stock exhaust. Hyd flat tappet 1,600-5,700 rpm range, 265/276 advertised, 211/227 @ .050, .442"/.462" lift, on a 110 LSA
Comp Cams 265DEH, Very strong mid range. Everyday performance for stock exhaust. Hyd flat tappet 1,600-5,700 rpm range, 265/276 advertised, 211/227 @ .050, .442"/.462" lift, on a 110 LSA
And @Dust Ya
400 hp is a 12 second capable car if it is not too heavy.
Id drop the ratio a half point. It’ll be a little easy with the best octane available. Even if you have 93 in town.
9.5-1, LD-340, 750 cfm carb, a mechanical cam @ 240@050 or a hydraulic cam at 248@050. Heads should be bowl ported. Gasket matching a plus but not mandatory.
If I was doing new pistons, I’d use the KB-107’s just below zero deck and a head gasket thickness to get the 9.5-1 ratio. These pistons at zero deck and 72cc J heads with a .038 head gasket deliver a 9.8-1 ratio. I have done this before. (With a .030 overbored 360.) But you need to check, measure and be sure of everything.
Back when I did this, I also had a LD-340 with the MP mods for the milled divider and a TQ hog out, MP Purple 292/.509 hyd. cam and super comp headers at 1-3/4 into a 2-1/2 exhaust. Same heads and it was a zero deck piston engine.
(Backed by a 4spe and 4.10 gears.)
Sell the Comp DEH and roll the money into a new cam.
I’d have the new cam ground on a 108 LSA.
Also, FWIW, the Weiand is also a very good manifold.
1 last thing, get a custom converter, it will make all the difference in the world. Converters can make or break a good performing car.
I’d have the new cam ground on a 108 LSA.
Also, FWIW, the Weiand is also a very good manifold.
1 last thing, get a custom converter, it will make all the difference in the world. Converters can make or break a good performing car.
Man good going. You have been making 400 HP 360 recommendations for 18 years. I just came from a post in 2004 where you were doing the same thing. MOPAR CHAT, 03-05-2004, around 11:00 AM I believe.
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Thanks Jim. I used to haunt MoParchat a long time ago. Yes, very active over there like here. I’m 56 and into cars for just about forever. I’m pretty familiar with a nice street build and power in this area. I hope to increase that ceiling in the future.
I’m sure my recommendation list has changed some.
I have paid attention to the then “old guys” and now I’m approaching that age. Certainly I’m still young, though 20-something’s look at differently. LOL!
I’m sure my recommendation list has changed some.
I have paid attention to the then “old guys” and now I’m approaching that age. Certainly I’m still young, though 20-something’s look at differently. LOL!
autoxcuda
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Thinking out of the box some....
Trade LD340 for Edelbrock RPM plus $200 net after all shipping costs. Same performance and you could spend $200 toward reaching your goal. Versus trying to impress someone with what's written on your intake.
Then cc the head.
Then check how much you could surface the the heads with slight ovaling of intake bolts to get to 9.5 compression. Make a business decision whether to surface heads
Spend ~ $275 on cam in range of Comp XE268, Lunati Voodoo 10200703 .... or spend a little more and give Bullet Cams a call to see what they suggest off the shelf and have piece of mind on the quality and the cam decision.
Trade LD340 for Edelbrock RPM plus $200 net after all shipping costs. Same performance and you could spend $200 toward reaching your goal. Versus trying to impress someone with what's written on your intake.
Then cc the head.
Then check how much you could surface the the heads with slight ovaling of intake bolts to get to 9.5 compression. Make a business decision whether to surface heads
Spend ~ $275 on cam in range of Comp XE268, Lunati Voodoo 10200703 .... or spend a little more and give Bullet Cams a call to see what they suggest off the shelf and have piece of mind on the quality and the cam decision.
LIKE!
Though I’d still get rid of that cam. NOT a good choice.
(IMO, the smaller cams recommend need a really good head port to make 400 HP. No matter the cam chosen, get a well known head Porter on board to get the best bang and head flow for the money spent.
Your cylinder heads will make or break the engines performance in a big way. If you find the porting price is distasteful, look into selling the heads for a set of trick flow heads. OOTB, there head flow will cremate very well ported iron heads for a reasonable price. Just lift the valve up to take advantage of the heads capabilities.
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