Hey guys,

I was looking to bump up the power in my 340 and try to get as much as I could out of it for at least a little while before trying to build something else. I barely drive the car and even more rarely race it, but I want something that'll hang with my friend's rides when I do go to the track. I don't mind building something on the extreme side as it sees so few miles anyway.

I'm on a very limited budget with having another project car that I am building, but I came across some w2 heads on the forum that I thought may be a good deal. I'm just not sure if I am opening up a can of worms with them.

right now I have a fully forged 340 with speed pro pistons and mildly ported J heads. The W2's I am looking into are Econo versions and are flowing around 290+CFM at .600 lift. They also come with complete valve train/rockers for .650 lift roller cam and a ported Indy intake.

My questions is, how would these work and what will I need to get them to work on my LA 340?

I know I'll need a bigger carb than what I run now, and I'll have to weld up a new flange to my headers.

What I am more worried about is cam and compression. I am pretty sure the 340 I have now was built with flat top pistons and my C/R is around 9:1 with the J heads. I also have a flat tappet cam. What would I need to do to convert to a roller, and would these heads even do me much good with my current compression?

If it won't cost me an arm and a leg to swap to a roller cam, I don't mind eventually refreshing the short block and having it rebalanced for some higher compression pistons. For now though, I don't really want to get involved with building a new short block.

Thanks and happy new year!

You have the idea for most of it.. if you want to
bump up the compression some you can have the heads
cut some.. make sure you do the intake side also.. you
will need push rods for it but you have the idea for the
rest of it.. it will want to turn higher to utilize the
flow with the stock stroke.. no big deal but you would
still need to remember you have stock rods... I ran my
stock stroke 340 with 10.0 compression and it ran fine..
it ran 10.0s at 2600#.. might have gone quicker but I had
to stay at 10.0... at 290cfm thats not bad.. I had 310 out
of mine.. you would like a steeper gear and a conv with a
nice stall.. if you dont get a nice stall it will be a PIG
off the line... just ask question and we can help out...
by the way.. my stock stroke I had Viper rods in it and it
ended up tearing a rod in half.. that was 7600 rpm

Yes, it will be a can of worms . The engine is going to want to turn some rpm"s, depending on your cam duration. What is the rest of your combo?

Thanks for the replies!

MR_P_BODY and viperblue72, I don't believe I have stock rods but I won't know for sure till I tear the engine down to refresh it when doing the heads. The engine was built many years back by a good friend of mine who also happened to be my boss at the speed shop I worked at. On the build sheet, he had Eagle rods and Speed Pro pistons listed but no part numbers. He died of cancer a few years back so I don't really have any way to find out what pistons are in there or if they are I or H beam rods till I tear it down. The block is a 69 I believe and I thought he told me it was a forged crank (but again, won't know for sure till I see it for myself). It's bored .030 over. The motor was built in 03 bur probably has less than 8k miles on it.

I have 4.56's in the car with a 28.5" tire right now but I plan to swap in a set of 4.10's I have laying around here when the weather gets warmer. The 4.56's were just a bit too much on the street.

Stall is a 9" ProTorque that I haven't installed yet that was set up for my current engine but I can have it restalled before installing it with my built 727.

My friend was telling me that they have drop in roller cams for LA blocks that I could use. I also don't mind going to a solid roller if needed. the heads I am looking into come with 3/8ths push rods but I don't know if they'll match up with whatever cam type I decide to go with (cheapest option possible).

Thanks again for your replies! I appreciate the help

if they're the set (W2 heads) David Dean has for sale I'd say you're in good hands..... he's a good guy!

I had older W2s on a stock 340 short block with Speed Pro pistons. Not sure what the exact C.R. was but cranking compression ratio was around 180 psi. Pistons were above deck like a stock 340, not a dome but a pop-up style. Heads were open chamber, maybe 68-72 cc. Heads were not ported, have 2.02 valves so they were probably equal to a mildly ported stock head? Had the Mopar .557" solid cam in it, Harland Sharp rockers. Pushrods were 8.00" I shifted it at 7,200 rpm. Victor W2 intake, Proform 750 and TTi small step headers into full dual exhaust.

"Only" went 12.20 @ 110 letting off but I later found out (from the guy I sold the pistons to) that it had a broken piston ring in one hole so it maybe had 11's in it if all was good. Previous owner went a best of 11.97 but usually went low 12s.

Car is the '71 Duster in my avatar. 3,200 with driver and a full tank of gas, full interior, all OE glass, steel flat hood, no bar but frame connectors. 28" drag radials, stock front suspension, springs moved in. 904 with 5 clutch discs and a low gear set, T/A FMVB, 10" 3,800 converter and 4.10 gears that were changed from 4.30. Changing to the 4.10 was a mistake, it needed the gears.

If you turn a lot of RPM, might want to consider the crossover oil tube. Mine did not have it though and it was not a problem.

When I first bought my used W2 heads there wasn`t much done to them, my combo at the time was; 340 Block 12 1/2 to 1 compression. heavy TRW domed pistons, 627 lift roller cam, Strip dominator, 750 HP carb, 1 7/8 headers, made 527 on the dyno, went 10.70s in my Dart shifting at 7,500 : later put those heads on a 30 over 360 crate short block with a 590 lift mech. cam, with cast crank and stock rods 11 1/2 to 1 compression . Victor W2 intake went 10.70s also and made about 530 hp, after a spun bearing I went to a M/P forged crank with eagle rods and JE pistons still 590 lift cam, same heads, and still 11 1/2 to 1 made 549 hp 450 tq and went a best of 10.40 shifting at 7,000 I put over 900 runs on the motor and it still ran great. I just recently took it out and went to an R bock, 408 c i ,Indy 360-1 head, 600 lift mech cam, 950 hp carb , Indy 360-1 intake, same 1 7/8 headers, 9 1/2 to 1 pump gas motor. that has gone 10.70s lifting at the stripe. ( too much gear and rpms) I have since put 4.10s to replace the 4.88s it should go 10.50s but will be throttle stopped down to run 11.50s

11secdart and rmchrgr, thanks for the replies! I am really liking the times you guys are all running with the W2's. This is an E body so little heavier but if I can get anywhere near the times you all are running I'd be more than happy. If I did it, i'm thinking maybe I'd keep the 4.56's and see how they work out.

J body, yes they are the Econo W2's David Dean is selling. I am really leaning towards getting them if I can make it all work.

I am pretty sure this motor has H beam rods based on the price listed on the build sheet. I also only found one set of Speed Pro pistons for a 4.070 bore small block chrysler, so those are probably the ones I have. Using those specs I found a few website stating that a 65cc head would give me a 10.1 C/R (although all the compression ratio calculators I used assuming a .018 piston to to deck and .025 head gasket gave me around 9.7).


If I can really get 10:1 without milling anything, I think I'll be on the right track. In the future I don't mind milling or even installing higher compression zero deck or pop up pistons, but for now I wouldn't have the money to be doing that.

Realistically, how much power could these heads make on a 10.1 340 using the Indy intake and biggest cam that will work with my compression? It would be a dream to get this car into the mid-low 11's all motor, think that would be possible with the 4.56's and upping the stall? I am worried that A) I won't have enough compression without milling the heads and B) those heavy speed pro pistons are going to hurt the bottom end. What do you guys think?


Here are the flow specs

Intake

Lift
.300- 196 cfm
.400- 249
.450- 266
.500- 274
.550- 294
.600- 291


exhaust

.300- 154cfm
.400- 182
.450- 188
.500- 192
.550- 193
.600- 190

Yes, IMO,I went 11.30s with a 340 9 1/2 to 1 compression and ported " J" heads, 557 lift M/P purple shaft cam, 8 inch convertor ( 4,700 stall ) and 4.56s. The Indy intake is a nice piece and works well but is tall, taller than my Victor W2 with a two inch spacer. So keep hood clearance in mind.

I mean340. Your going to need all the specs for a calculation of the ratio to be correct. Which would help out greatly for cam selection and fuel requirements. With those head specs, I would think you can create a pretty good and fast ride that will meet the goal of a scary ride from the passenger seat. Your going to spin some rpm with that set up!

What headers do you have now?
What are your cam specs?

Thank you 11sec dart! I would be very happy with times like that. My e body is a bit heavier I'm sure, but it has some light weight Weld wheels and no AC so it shouldn't be a pig either. I'm working on the hood clearance issue, but a forum member suggested I could mill the plenum down 1" if needed.

Rob C, I probably won't know the true specs till I tear it down, but I am 99% sure my builder used Speed Pro L2316F30's as it was really the only off the shelf forged speed pro piston I could find for a 4.070 bore Chrysler. We were originally going to run some nitrous on the motor, and given the price on the build sheet I am pretty sure the forged ones are the ones he went with.

Stroke is 3.313 divided by 2= 1.656
Compressed height = 1.840
Eagle rods at stock length (again, pretty sure)= 6.123
so that gives me 9.6195

Assuming a stock deck of 9.6, this puts the piston out of the hole .0195.
Using a .043 compressed height head gasket, a 65cc chamber puts me at 10.09:1

with a .025 head gasket I could jump up to just under 10.6:1 and if I mill the head .020 I should be able to get close to 11.5 according to the calculators assuming I have adequate valve clearance for all of this. I want to run on 93 octane pump gas or at worst, a 50/50 mix, so I don't even know if I'd want to go that high.

What kind of cam should I be looking into with this? The springs on the heads were set up for .650 lift. Not sure what I could do as far as mechanical roller/flat tappet or what. I don't mind going with a solid lifter if that is the cheapest/easiest way to go. I don't put many miles on the car and an occasional valve lash adjustment won't be the end of the world.

If your pistons are .019 out the deck you do not want to run any less than .054 thick head gaskets unless you are positive the open chamber will let the piston in the open chamber area. If they are closed chamber you definately can not run less but that would be good as you will then have nice quench area/distance. In that case you could mill the heads down more to get more compression, all the way down till almost in the valve seat.