On ebay there is a 73 514 stroker block. Appears to have std. bore pistons and has a 514 stroker crank. I have a 91 F250 with a 460. Could I yank my heads, ect off and put them onto the stroker block so it would basiclly just be a 514 block with a EFI system?

 

Moved to proper forum.

 

yes you could put your EFI heads on it you might have to mill the intake to make if fit properly. but hte issue is gonna be in the fuel injection itself the ecu isn't gonna be calibrated for the larger CID, and the most likely bigger cam etc so that would have to be upgraded, possibly needing bigger injectors there is a lot of issues with doing that but physically yes you can bolt it on.

 

If the 514 block is actually a 460, with a stroker crank, rather than a fancy racing or aftermarket block, your EFI heads will bolt right on. You'll need to retain your EFI intake with those heads however. The blocks are similar enough across the entire year range of production you can mix and match as you wish, but the carb intakes have to go with carb heads, and the efi intakes go with the efi heads. There are also industrial heads for the 460, some of the newer ones have open chambers for a lower compression engine, but have the EFI intake port style, which is why I'm using them on my 500cid stroker - better flow, lower compression, yet I can still retain my EFI intake.

The EFI system you have is speed density, so the computer makes assumptions based on the vacuum it sees in the intake, as to how much fuel it has to add. The major assumption is the displacement.

The injectors (E8TZ-9F593-A) are 24lb injectors, so if you increase your displacement by a certain amount, you need to increase injector size the same amount. So in your case....

514/460 = 1.12

24lb * 1.12 = 26.88lb injectors.

You can do this by replacing the injectors for about $400 or so, or you can be a little sneaky and increase your fuel pressure on the rail from the factory 45psi to 55psi. I'll save you all the math involved but if you can find a 55psi regulator (or an adjustable regulator and set it for 55psi) you'll have the same result with the existing EFI injectors you have now.

The most important thing with speed density EFI is NOT to run high overlap cams. I know a lot of us want a lumpy cam, but this causes the vacuum to pulsate all over the place at lower RPMs and the speed density EFI is going to freak out. Usually a little overlap is okay, but too much will result in you pulling your hair out.

That's why those of us who want some serious engine work done (by a shop or our own hand) and retain fuel injection, often convert the truck from speed density to mass-air, using a Mustang EEC computer (89-93) and adding a mass-air flow sensor in line with the airflow. The mass airflow sensor measures the air sucked into the engine, and is very tolerant of engine modifications. And the side benefit, is if you want to really tune the EFI, there are products on the market that will allow you to dig into the data tables to adjust the EEC appropriately for your very large engine.

eec-tuner is one, tweecer ($400) is another, and there are a few more as well.

I just won a mustang mass air computer on ebay, it should be here the 19th.