I’m very young and new to building engines, I need help trying to figure out how to measure valve clearance on a 390fe, stock block, pistons and rods, full comp cams valve train, with a 270h .519 cam, patriot long tube headers, HEI distributor, plugs and wires to match and Cometics .027 MLS head gaskets, still using stock intake and carb for now but will later be upgraded to 4 barrel AVS2 carb and Edelbrock aluminum intake when I have the money. Pictures of everything can be provided, I’ll do my best to answer any questions.

 

What rockers? Are you trying to set clearance or find pushrods? What heads? Hydraulic or solid tappets a roller cam conversion? If the rockers are not stock are they adjustable? With yourcmods you probably need to be just as concerned with pushrod length as you do clearance. Provide some more details and then we can provide more accurate recommendations.

 

they are the stock rail mount rockers, non adjustable 1.73rr, I’m just trying to make sure nothing explodes in a big ball of fire if you get what I mean, I’ve only built 1 other engine besides this one so I’m not super confident.
also the cam is a hydraulic flat tappet.

 

There is a fairly quick way to check your valve clearance. Set the engine to #1 TDC. Using some creative tooling, rotate the rocker arm away from the valve tip as far as it will go. This should push an oil out of the lifter as it bleeds down. I don't have the number right in front of me but there is a clearance range that you must have between the rocker tip and the valve tip. In this related thread they indicate a 0.10" to 0.20" gap between the valve tip and the rocker. If you look at the preload on the lifter and the rocker ratio this ensures that you have some preload and not excessive preload. If you are less than 0.1 or greater than .2 you will need different length pushrods. If you do some google searches of if you have a service manual the preload check is shown. The stock rockers are supposedly good up to about .550 lift but with your cam, springs, and lift you may need to look into new rockers in the future. Even if they are adjustable you will still need to check pushrod length to ensure that the rocker is sitting at the center of the valve tip.

Here is another link showing the procedure and has the clearance specs shown as .119 to .219. https://www.ford-trucks.com/forums/1...-settings.html

Since you are not running a stock cam I would probably do this at TDC for each piston rather than the multiple checks shown in the procedure from the manual. On a radical cam you'd need to find the base circle for each I and O valve at each cylinder. TDC should be fine for your application.

 

alright thank you very much, I haven’t been able to find a manual on it yet but I’m going to keep looking, so far threads have been my main source of information, but am following them loosely just Incase.