Posted By: bill8121
j heads - 07/22/12 05:00 PM
Hey guys i just wanna little input for my build. I'm starting from the ground up with a 408. I have a nice set of j heads and am wondering if i should stick with em. I know there's better but how much more power will i get for the money i would spend. And if i do go with aftermarket heads will it make a night and day difference? Let's say i put 1000$ into the j heads. 2.02 valves, port matched and milled. 030. I'd still have the flow of the big valves and decent compression. I'd like to stick with the stock valve train. Or would it really be worth the extra 500 for rhs heads? Please keep in mind I'm new at this. I'd like to get about 450 hp at the rear wheels. Also keep in mind i haven't even started the build yet. Just getting a plan together. Thanks in advance.
Posted By: RUNCHARGER
Re: j heads - 07/22/12 05:02 PM
Personally I think if you have to spend more than $300 getting the iron heads usable that you're better off putting that money into something new.
Sheldon
Posted By: Dartcuda
Re: j heads - 07/22/12 06:27 PM
You can get the RHS heads ready to run for $1100 which by far is the best bang for your buck.
Posted By: DakFink
Re: j heads - 07/22/12 10:04 PM
Stay with the J-Heads and put them in the right hands for some port work.
Just so Happens I was at the Local RoundyRound track watching Modifieds last night and the Only Mopar in the field was Running a 360 with J-heads in an Unlimited Alcohol class. Rules in that class are limited to Steel Block and Steel Heads other than that; run what you brung.
He could have easily been a front runner had he wanted to and been a regular racer. He'a was a casual racer "comes out when he gets the urge. Either way on a 3/8 mile oval he was getting passed by 1/2 the filed in the turns BUT passing them back up on the straights. I was IMPRESSED.
Only other Iron head I would consider is an R/T 2.02 but they are no longer available NEW.
I don't know much about the RHS heads: I would call Brian @ IMM or some other head porter that has lots of experience with them and the J's and see what they have to say.
Dang smallblock heads have gotten to be a MESS as of late.
Posted By: dogdays
Re: j heads - 07/23/12 03:46 PM
I also think Brian at IMM, board name OU812, has the answer for you. Get in contact with him, he is a professional engine builder and knows his stuff.
R.
Posted By: 5spdcuda
Re: j heads - 07/23/12 04:38 PM
I think you're being unrealistic in thinking you can get a set of 40+ year old heads to do what you want for only $1,000.00. To start with you will need hardened seats and almost certainly new guides. Add in milling, possibly both block and intake side and you already have real money involved and all you've done to this point is get them back to new condition. If you don't mind the weight get the Engine Quest/RHS heads. Good valve job and bowl/port work and they will make good power. Personally I don't like weight, especially up high on the engine. I do like easy repairability. So for me it's aluminum. If you already have some good rockers I would get a set of bare Eddys and put in a set of PBM valves [ light, good flow, and reasonably priced ]. Minor bowl/port work and you're good to go. If you need to buy rockers, consider the Indybrocks. Again get them bare. Indy's valves are durable enough, but HEAVY and not as good a flow as PBMs. Indy's come with a 2.05 intake, slightly better intake port/flow and the rockers [ stock big block dimensions ] will work fine with reasonable spring pressures. I've got 50,000 miles on mine. They also have 3/8 hold down studs vs. the standard 5/16 bolts. Cheap speed is an oxymoron, or at least cheap, DURABLE speed is.
Posted By: LA360
Re: j heads - 07/24/12 12:24 AM
The $$$ you're talking about spending on your heads aren't going to get the results you're talking about. Look around for a used pair of W2 heads or something similar.
Posted By: bill8121
Re: j heads - 07/24/12 01:02 AM
Cool. Good info. I know the j heads are worth something. Thanks for the help. I'm gonna be working with Brian through this build as he is fairly close. When i do start i'll start a thread.
let me know what you doing with the 'j' head,
I have a project in mind !
Posted By: bill8121
Re: j heads - 07/24/12 02:07 AM
Ok. It's gonna be a bit though.
, but you will still have to do some minor bowl and port work to get to the 450HP level. Still a good buy though. J heads would take considerable more work, but you could get there with them too. The port work on the RHS heads you could probably do yourself, as most of it is blending and minor bowl reshaping.