Hey all, Can someone tell me where to find the 1.94 intake and the 1.60 exhaust valves ? SI valves actually has the 1.94 valves, so i am really only looking for the 1.60 exhaust valves. i see vintage inlines has them both out of stock,any ideas guys ?

 

Moved to appropriate forum

 

The SI part number for the 1.60" exhaust is SEV-3005
Last time I talked to SI they were selling those valves exclusively to Vintage Inlines.
If you can't get the 4.810" long Ford 300 1.94"/1.60" valves from SI then we use the SBC 4.910" long valves instead.

What camshaft will you be using?

 

camshafts,so many choices i was confused to pick one would it be needed with valve change if so what do. you think would be best, my truck is a 78 f100 stepside shortbox i have a clifford intake with twin 32 webers and headers 2 1/4 exhaust.i dont tow anything i actually tow it behind the motorhome. if i use the sbc 4.910 valves instead what parts do i need if i use them. thanks mark

 

You want to take advantage of the twin weber and header combination with a moderate cam.
I would recommend the Schneider 135H (13919) .472"/.472" 214/214 270/270 110deg.

Here is where the extra work begins.
The stock rocker arm studs are press-in and there is a concern about the studs pulling out of the head with the extra valve lift and spring pressure needed with an aftermarket cam.
It is recommended to convert to screw-in studs.
Use the Comp 942 valve springs with the Comp 768 retainers.
The valve spring should be installed at a 1.750" height.
You may need to shim or use a .050" down keeper to get the correct retainer height. You will find out the right approach after the valve job is done and you can check the retainer height using the stock keepers.

Or you can buy the Promaxx CNC ported big valve head and save yourself a lot of work.
The performance increase throughout the power band will be significant.
https://www.ford-trucks.com/forums/1...l#post19738909

 

Yea i think you got a good idea on the promaxx head, i have been looking at that one on my screen for a while now, looks like a fairly good price for all the pain it will save me.so go with the comp cam and new rods. any thing else i need ?

 

I think you mean the Schneider 135H cam?

If you use the Promaxx head you will need the stock pedestal mount rocker arms for the 1985 and later EFI heads along with longer pushrods.

 

typo thought yes i ment Schneider 135H cam ok then
need the stock pedestal mount rocker arms for the 1985 and later EFI heads along with longer pushrods. thankyou

 

Here are the stock pedestal mount rocker arms with pivot and bolt.
Ford 300 CID 4.9L Complete Rocker Arm Kit 1985-1996 - 12 Rocker Arms | eBay

You will also need a set of channels that keep the rocker arm pedestals from turning.
These are the closest ones I can find. they fit the SBF and may have the same spacing as the six. If not the holes can be elongated a little more to fit.
Ford Performance Parts M-6588-A50 Ford Performance Parts Rocker Arm Channel Kits | Summit Racing

Here are the Scorpion roller rockers that have a 1.73 ratio rather than the stock 1.6 ratio.
1059 – 1.73F Ford I-6 Rocker Arms – Scorpion Racing Products
FORD Scorpion Racing Products SCP1059 Scorpion Race Series Rocker Arms | Summit Racing

 

Thank you so much

 

are the stock rods fine with the Scorpion roller rocker kit ?

 

The last set of Scorpions installed on a stock EFI head needed a little longer pushrods.
A set of Comp 3/8" 10.250" long pushrods were installed. You will need to install the head first to see what you will need.
The stock 5/16" pushrods have less than a .060" wall thickness and bend easily.

 

ok got it thanks

 

Glad to see you are getting the Promaxx head.

You can start by replacing the manifold bolts with studs.
If there is a difference in thickness between the header and intake manifold flanges you need to make a step washer where the step in the washer is the same as the thickness difference.
This way the washer will put equal pressure on both intake and exhaust flanges.

I've seen oval washers made from bar stock that do a better job of spanning the gap between manifolds.