306 build intake question

[pennyduke]

1971 302 bored 30 over, Flat top pistons with 4 valve reliefs, GT40p Heads from a 99 Explorer. My question is that I want to use a stock 1968 Mustang 4v dual plane intake manifold on this setup but the intake ports are smaller than the ports on the heads. Should I gasket port them or just use them as they are? I've been searching the forums for days and found nothing on that manifold with GT40p heads.

Also what do you guys think about a small Thumper Cam? This 1970 bronco will only be driven around town and I would like it to sound mean. I'm not worried about going fast at my age. Thanks all

 

[Broncobowsher]

Personally I am not too worried about a small port going into a larger one. The other way around is not a good idea. A little clean up is probably fine but I would avoid full gasket match. likely for the airflow to catch a sharp edge going into the port and that really messes with airflow.

Never ran a thumper cam, but know the idea behind them. Sounds like a mean race cam at idle but has good drivability. A drivable car show cam. If that is what you want it to do, it is probably a good choice.

 

[pennyduke]

Thanks for the reply. When I bought the heads the nice guy sold me a edelbrock performer RPM intake to match it for $25. Do you think this would be a better choice than the stock 4v or would it be too much? Again I'm just looking for sound and drivability around town. Thanks

 

[mcknight77]

The Performer RPM would be the better choice as long as you have enough hood clearance.

 

[pennyduke]

So it took a while to get the motor back from the machine shop and I'm putting it all back together now. The old points distributer looks pretty bad. I was searching for the best replacement for it and I see a bunch of different choices. I would like stay with a close to stock looking but I'm open to all suggestions. Thanks everyone for all the help getting me to this point...

 

[DJs74]

So it took a while to get the motor back from the machine shop and I'm putting it all back together now. The old points distributer looks pretty bad. I was searching for the best replacement for it and I see a bunch of different choices. I would like stay with a close to stock looking but I'm open to all suggestions. Thanks everyone for all the help getting me to this point...

I'd vote for the aluminum intake manifold. Never ran a Thumpr camshaft but I think they are pretty popular - you might also check some of the "XE" series camshafts from Comp too, they are good performers and some have a pretty lopey idle as well depending on the centerline and duration you choose. As for the ignition system... I vote to convert to electronic ignition such as a factory Duraspark, MSD or something other than points. With all your upgrades in cylinder heads, intake, camshaft and the end result you are looking for... I say ditch the points. Summit Racing for example can walk you through matching up all the various components you need and no matter the brand, they all come with good installation instructions.


DJs74

 

[nrramse]

So it took a while to get the motor back from the machine shop and I'm putting it all back together now. The old points distributer looks pretty bad. I was searching for the best replacement for it and I see a bunch of different choices. I would like stay with a close to stock looking but I'm open to all suggestions. Thanks everyone for all the help getting me to this point...

Pertronix makes an "Igniter" that replaces the points in a stock distributor. I've been using it in mine for 20 years and only replaced it once.

 

[pennyduke]

Where can I find a dizzy with the igniter already in it? I would like to replace the whole stock dizzy because it appears to be pretty wore out.

 

[bronconut73]

https://m.summitracing.com/parts/pnx-d134600

 

[Biohazard]

I've heard good things about the thumper cams. I would say run the edlebrock intake, but you may have some hood clearance issues. As long as you're running a low profile air cleaner you should be fine. I'm running a GM style HEI distributor and have had good luck with it so far, but I had to run a smaller air cleaner to fit because the cap/coil took up so much room, and the new cleaner hit the hood brace. 2" bodylift fixed that issue. There are some HEI distributors that are designed to look like factory ford, and have a separate coil, though.

 

[pennyduke]

The motor is moving along pretty good, My front timing cover has a tube for a dipstick, The Bronco oil pan has one for the rear sump setup. Is there a way to remove the front tube and plug it off? Or will I need a new cover?

Thanks all!!!

 

[Rustytruck]

You can just pull out the front tube and fill the hole. some people fill it with Silicone, some use JB Weld and some tap and plug. There's not supposed to be pressure forcing oil out unless your PVC system is whacked.

 

[pennyduke]

My new oil pump came with a gasket that goes between the pump and the block. Should I use the gasket or not. I know that I was told not to use one on a Chevy 383 I just rebuilt. But that is a Chevy...

 

[Broncobowsher]

Use the gasket.

 

[77RHINO]

I'm fairly sure I used that gasket. Also, I filled my front dipstick tube with silicone, haven't had any problems. As far as distributors, when I built mine ('96 roller block so I had to swap on the '96 gear) I used a shaft and pickup from '83, funnel from my 77, and cap from a '78 ford. All ford parts from the parts store, and works like it should with my duraspark system. Since it sounds like your swapping timing covers, make sure your timing pointer and harmonic balancer are still accurate as well.

 

[pennyduke]

Ok, Thanks Guys.

 

[pennyduke]

Today I was trying to install my timing cover and it is hitting the fuel pump cam wheel leaving a 1/4" gap between the cover and the block. I don't understand how this can happen. Maybe the machine shop used a thicker cam plate when they installed the cam.

 

[pennyduke]

I just laid the new comp timing sprocket next to the stock one on a flat surface and the new one has a 1/4" lip sticking out past the stock one. Anyone else ever have this problem?

 

[DirtDonk]

Two different timing gear set styles was the common reason from what I remember. It was always on a piece of paper that came with the gears I ever bought, as well as mentioned in the rebuild books. Said to check to make sure that the new matched the old.
I'm assuming that cover clearance was the resulting issue, but I never actually found myself with the wrong gears before, so don't know all the little details.

Check with Comp and see what they say. Or look in their catalog/website to see if they list two different ones.

Did the two sprockets line up correctly too? I assume they did or you'd have noticed a misalignment of the chain and/or it would not have installed easily. If they are correct then I guess the lower gear is matched with the depth of the upper.
Plenty of members here with more engine knowledge about the little quirks of our setups. I'm sure you'll get some direct info you can use.

Good luck.

Paul

 

[pennyduke]

I just called the machine shop and they confirmed that I need the smaller thickness gear. He told me to bring both of them in at 3:30 today and he will give me a new one or machine the new one I have down to match the stock one.. He said this happens a lot when you switch to a double roller timing set. Thanks for the help, I'm sure I will need more.