New street class pulling truck motor

I've been gathering parts over the winter for a new motor for my '79 F350. I like to pull in the local stock classes, but the Chevys are eating my stock 460 alive. I have to stay with iron heads, iron intake and exhaust manifolds for the stock classes around here, so here's what I've picked up so far:

-Iron Cobra Jet intake manifold (OMC boat intake)
-73-74 Police Interceptor Exhaust manifolds
-Used .060 over short block with low hours - stock rods/crank with forged Sealed Power domed pistons (-12.1cc), all ARP hardware in rods/mains

My plan is to run a set of D3VE heads on this short block to get the compression down a little. The guy I bought the motor from said that the compression worked out to around 13:1 with D0VE's on it. If I have things figured right, I should be in the upper 10s for SCR.

So next step is setting up heads and cam. Money is tight for me right now, so I was planning to port the D3 heads at home using Scott's porting guide on RHP's site (I did a set for my 2wd '79 and they worked good), do a 30* back cut on the stock valves, and polish up the combustion chambers (to prevent detonation). Thoughts?

Oh, and I should also add - the truck has a C6, 4.10s, and 33" tires.

I have no ideas on cam yet - but here's what I'm looking for - I'd like to keep the idle pretty mild. Some places will bump to modified class if the idle is too crazy. What should I be looking for in cam specs? Also, what do I do about valvetrain? Can I run stock rockers? Am I way off base?

What fuels are you allowed to run? are you allowed to run rollers cams?

Must be gasoline, but high octane like turbo blue and cam-2 are permitted. I'd like to stay closer to pump gas 94 if I can with this combo since it will get driven on the street, will it be possible? I don't see anything in the rules against running roller cams, so I think its ok.

We then compression and a roller cam are your friends.

You can mill the domes off of the TRW type pistons to get the compression down and use DOVE or Iron CJ heads.

any Vacuum rule?

Ok, what about using D3 heads with the current domes to keep the compression in check? The only reason I'm considering this route is cost. I have a set of good D3s, I don't have D0VEs. Not sure the current funds will allow for a set of good D0VEs (I'm certain I can't afford Cobra Jets) plus milling the pistons. I know the D3 don't flow great, but if I work them a little can I make them work good for this engine?

No vacuum rule, but a really raunchy idle might bump me up at a few places. I'm planning to put a good set of mufflers on it to keep the masses off my back if it does idle a little rough, but if it shakes like a top fuel car I'll get bumped into modified classes for sure (I definitely don't have the cashola to play in that class yet).

In general, what are the benefits of running a roller over a flat tappet, purely efficiency?

The d3 heads will flow just as much as doves they just have a bigger combustion chamber so they work better for pump gas.
In my area you have to have high compression and a big roller cam to be competitive in the stock class truck pulls, every one trailers their "stock" trucks to the pulls. you might have to do the same to be competitive.

D3's will work if your funds are tight.

I'd stick with a Flat Tappet Cam too (For Cost Reasons). Call Randy Malik (RM Comp 586-909-1591) for the Cam / Valvetrain parts, hes done a number of Exhaust Manifold Cams and is a great guy to deal with.

That is pretty much the norm here as well. But there are a few places I like to pull at that do not allow trailers, so I will have to drive it on the street occasionally. If I can get it to run on Premium with a little Turbo Blue mixed in for insurance I'll be happy. I think the domes and D3s will get me right around 10.5-11:1, which should be just pushing the limits of pump premium, right?

By "big roller" what do you mean ballpark-wise. I'm really in the dark as far as what cam will work well with this setup... Like I said, a top fuel idle will get me bumped at a few venues.

Stick with a Mechanical Flat tappet, much cheaper if your on a budget.

dfree383 wrote:D3's will work if your funds are tight.

I'd stick with a Flat Tappet Cam too (For Cost Reasons). Call Randy Malik (RM Comp 586-909-1591) for the Cam / Valvetrain parts, hes done a number of Exhaust Manifold Cams and is a great guy to deal with.

Cool, thanks for the help, I'll give him a call to see what he can do.

Sanity check - Am I in the ballpark compression-wise for a Premium pump motor at 10.5-11:1

Yes, But Alot depends on your tuning ability and parts used.

Also, ya might want to put some more gear in the truck. 4.10's with an auto in low range first gear is like a 4 speed in 2nd gear low range with @3.08 gears. You probably need to be in the 4.88/5.13 range which I know is not very street friendly, if you wanted the best of both worlds you can swap in a 208/1356 transfer case which has a lower gear ratio in low range then your 205 case. The 208/1356 is not as strong but at your power level-I would say it would last a long time.Then you can drive on the street with your 4.10's & pull it in low range & you'll be geared pretty good. You should also look into a decent converter to help get the rpm's up. -A

dfree383 wrote:Yes, But Alot depends on your tuning ability and parts used.

I'm planning to polish the combustion chambers to eliminate any sharp edges that might create hot spots. I'm also going to take it to a local performance shop after it's done to have it tuned. A buddy of mine owns the shop and has a ton more tuning experience than I do (near zero).

4speed wrote:Also, ya might want to put some more gear in the truck. 4.10's with an auto in low range first gear is like a 4 speed in 2nd gear low range with @3.08 gears. You probably need to be in the 4.88/5.13 range which I know is not very street friendly, if you wanted the best of both worlds you can swap in a 208/1356 transfer case which has a lower gear ratio in low range then your 205 case. The 208/1356 is not as strong but at your power level-I would say it would last a long time.Then you can drive on the street with your 4.10's & pull it in low range & you'll be geared pretty good. You should also look into a decent converter to help get the rpm's up. -A

Thanks for the advice, but I really don't want to go that deep with the gears right now. There are a few pulls I have to drive to, and I also like to cruise it some on weekends too. It already turns 3000 at 70 with the 33s. The 208/1356 is an option, what were these used in? I have a case from an 86 Bronco is this a 208? I also have a 203, and I've considered building a 203/205 doubler, just afraid that some guys would complain if I showed up with a transfer case doubler. A converter is definitely on the list. Planning to order one once I figure out how the motor comes together.

Something else you'd might want to consiter, a 2nd set of tires. One set (larger dia) for the street and smaller for the track. It basicilly the same as changing the gearing and you can get the desired rpm for crusing. Just make sure your speed-o is calibrated for the tires that you'd be using on the street.

X 2 on the second set of tires. I used to run 35" MT on the street and switch to 31" tall at the pulls. This was with 4.56 gears.

rmcomprandy wrote:

If you are going to use D3VE heads and you need to keep the idle sound just above stock, you may as well get a "custom" flat tappet hydraulic lifter camshaft to do what you need it to do.
The more the compression you feel comfortable to run then the more radical the camshaft can be and still retain a stock type sound for the class.

Thanks for the input Randy. I assume you have some "ideas" on what will work for this engine? I need to get a measurement on how far the pistons are sitting in the hole so I can figure out the final SCR. Then I will give you a call to get a cam rolling. I saw your website and the "custom" hydraulic flat tappet cams are well within my budget, so that's the way I'm gonna go. You'll have to let me know what I need valvetrain-wise to work with whatever cam I need.

I assume that once we get the cam figured out, you can give me a suggestion on where I should be for stall on the converter?

You won't be sorry.

I've been where your at so I think I can offer some insight.

1. You need to go with the 1356 transfer case. It will hold up to the power you are throwing at it, and it has the 2.72:1 reduction you need. If you stay with your current driveline, your final in 1st and low is 19.97 which is way too fast for power your motor will be making. With the 1356 case, your final will be 27.43 which really is still too fast for your motor, but still much better than with the 205. Also, If you have looser tracks out there in Pa, then you will be fine. Also as someone else already mentioned get at least a 3200 stall converter. I'd like to see higher, but until you know what rpm your motor will turn in the middle and at the big end of the track, I don't recommend going higher. Normally the cam specs determine the stall, but pulling is different than street or drag and you really need the rpm as you come out of the hole, but also you don't want the stall higher than what your motor is pulled down to at the big end.

2. Tires. as was said earlier get a set of 31's to go with your 33's. Looser tracks your 33's will be fine but on a tight track you won't have the motor to pull them so the 31's will be preferred.

Also, you may already know this, but in case you don't, I'll say it. RPM, RPM, RPM. That is a big part of pulling. Pulling is about momentum, and you need ground speed to get it. Since you don't want to try shifting, the only way to more ground speed is through motor rpm (assuming your tires are hooked to the track). Larger tire size will help with ground speed, but only if your motor can maintain the same rpm that you were turning with the smaller tire. Here is an example. Say your turning 6000 rpm with 31's and a c6 and 1356 tcase, your wheel speed will be a theoretical (ideal conditions) 20.17mph. Now put 33's on it, and your motor rpm drops 500 rpm, now your wheel speed is 19.68mph. You lost ground instead of gaining.
On the cam, I'd suggest going with a solid flat tappet because with a custom grind, you can make more power and still maintain a relatively smooth idle. With your exhaust, can you add cut outs? If so, then you can run quieter mufflers for when on the road, and straight dump when on the track. If not, then get a short bullet type racing muffler to reduce backpressure and turn down after the muffler (but behind the cab)

Thanks a ton for the insight. I really appreciate all of the suggestions, especially from the guys that have been there. Most guys are pretty tight-lipped about setups, so it is good to find someone who is willing to help.

I am already planning the transfer case swap, but I'm going to use a Borg Warner 1345 t-case instead of the 1356, for 2 reasons: 1. I already have a 1345 in my parts stash (free!) 2. The 1345 has a fixed output yoke, so I can reuse my current driveshaft. From what I've been reading, the 1345 has the same 2.7:1 low range that the 1356 has. I do also have another set of wheels laying around, so I'll have to see if I can pick up a set of 31s to throw on them for the tight tracks. I'm also considering throwing a low range gearset in the C6 - from what I've read, I can swap the internals from an E4OD to make a wide ratio C6. This might get me closer to the ideal low final drive ratio without sacrificing my street ability.

1345's are not quite as strong as 1356's. the aluminum vs magnesium case...although the 45 has more case ribs.
they are not actually the same ratio, and do not use the same chain.
ratio for the 56 is 2.62 or so and the 45 is the 2.72 ratio.
Parts are not as plentiful for the 45 either.
however i think it'll do just fine for a while.

If you are wanting to run 1410 joints i don't know if you can find 1410 yokes for the 45 either.

I'm hoping that with the power levels that I'm at, the 1345 will last for a while. If it does go, I'll have to try to track down a 56. I'll be running stock u-joints (1350) for now, at least until I break them.

Alan, no go on the exhaust cutouts. Rules specify that I have to run through a full exhaust with mufflers. I was planning to run a little quieter muffler, not for quietness on the street (couldn't care less about that) but to keep the techs off of my back if the idle is a little rough. If it sounds wicked, I will get bumped up to the next class.

Also, I measured the deck clearance tonight, the piston are sitting right at the top of the hole. That means that the compression will come in at 11.1:1 with a .050" thick head gasket. I know this is pushing it for pump premium, so I'll probably have to mix in some race gas at the pulls to keep it healthy. I'll back the timing off and take it easy on the street when running pump gas. I think polishing up the combustion chamber will help as well.

Alot of the Rough Idle stuff can be taken care of by tuning everything and getting the proper camshaft, rough Idle doesn't mean big power......

Randy is setting me up with a cam now. It will be up to the dyno shop to figure out the tuning. I'm not a tuning expert (yet- haha).

I have a set of old TRW dome pistons in my mud truck engine. I did not zero deck the block and I wish I would have. I don't hear any detonation with 93 octane fuel while mud racing it on the flat track. Some kids up the street got stuck the other day and I went up there to pull them out and while the truck was digging down and making 3' deep ruts it had some detonation. It has 35" boggers for tires.

Get the thing "0" decked to help eliminate detonation it wont cost but about $100 - $150.