460 truck blocks

Hi, question for you Ford pros. I have a 1984 460 in a F250 Ford Pickup. It is in need of a replacement rear oil seal. I have oportunity to buy a 1977 engine mint looking condition no oil leaks and clkean. Will 1977 engine fiit 1984 460 pickup? The 1977 460 came from a Pickup camper special. Thanx OH I am going to run on Propane fuel. Any tips? This is my Tow vehicle. Thanx Mike

madman wrote:Hi, question for you Ford pros. I have a 1984 460 in a F250 Ford Pickup. It is in need of a replacement rear oil seal. I have oportunity to buy a 1977 engine mint looking condition no oil leaks and clkean. Will 1977 engine fiit 1984 460 pickup? The 1977 460 came from a Pickup camper special. Thanx OH I am going to run on Propane fuel. Any tips? This is my Tow vehicle. Thanx Mike

It will directly replace the 84 engine ... neither was built for Propane usage.

Everything will swap, it all is the same.

Why replace the whole engine if all you need to do is fix a leaking rear main? They are not hard to replace. What are you going to use for a propane mixer?

For replies, it appears the replacement engine has factory fuel pump block of plates ?? This is a 1977 engine im looking at swapping. The current oil leaking 460 has been in the Truck running on Propane and Dual Fuel since 1984 I run a impcoe mixer and it runs a 780 holley carb (I think thats what it is) Had it rebuilt a couple years ago, Get good mileage with it, Headers sure suck always troubles with them leaking rusting and so on, Gonna go back to truck manifolds,may machine slots into bolt holes so when they expand they wont crack ? Think that would Help mill the slots a bit 40 thou or so each way so manifold can move when hot ? Anyone recomend a decent exhaust stytem to use with stock truck manifolds? Im after Mileage. I have gotten mighty good mileage out of that Old truck, I run bit larger tires, keep tuned well, It runs at about 2100 rpm on my Tach at 60 miles an hour, Now someone said why not just replace the seal? (Rear oil seal) WELL after all the Bullshit with headers (3 days it took to drill out the broken header bolts last time) Im so sick of them , Unless theres a smarter better way of mounting them? Maybe unisert thread inserts in the head and Black anti seize. ? I really like my old 1984 Pickup and it has never let me down. I drive it all year (Minus 20 and colder) in winter and it has NEVER failed to start either on gas or Propane, Im planning on building a propane engine from ground up with the 460 original 4 bolt block im removing and droipping ion the 460 I found 68000 miles on it for quite cheap. Shall see Thanx for the comments Guys Thank the Lord for the Big Block Ford...!!! MikeHa Ha

A 1977 460 engine is NOT a direct replace for a 1984 460. The 1977 will be internal balance and the 1984 will be external. Ford changed to external balance on the 460 for the 1979 model year, so you will find some engines built in 1978 that are external.

To use the 1977 460 you will need to use a flexplate or flywheel that is zero balanced. As for use with propane normally the heads would be fitted with hardened valve inserts and SS valves. Using the stock heads may work in light duty use for awhile, but valve recession can still be an issue.

madman wrote:Hi, question for you Ford pros. I have a 1984 460 in a F250 Ford Pickup. It is in need of a replacement rear oil seal. I have oportunity to buy a 1977 engine mint looking condition no oil leaks and clkean. Will 1977 engine fiit 1984 460 pickup? The 1977 460 came from a Pickup camper special. Thanx OH I am going to run on Propane fuel. Any tips? This is my Tow vehicle. Thanx Mike

Food for thought: The 1977 engine is internally balanced, while the 1984 engine is externally balanced. Therefore, you must retain the parts of the rotating assembly with their respective engines--from the harmonic balancer to the flywheel and everything in between--that came with that engine. In other words, if your 1984 F250 has a T-18 4-speed (ext bal flywheel) and the 1977 Camper Special had a C6 (int bal flexplate), bolting the 1984 flywheel to the 1977 engine would cause an imbalance and the engine would shake. Keep the two engines are their parts separated.

Paul

Buy a good quality set of headers and have them ceramic coated, that will solve the rusting issue. There are plenty of good reputable header builders out there. As far as leaking, don't use a gasket, just use silicone, and a good hi temp anti sieze to keep the bolts from rusting.

SO me being new at this with 460 s ,You are saying i must replace the crankshaft with all the bits from my 1984 and stick it in the 1977? Hm sounds like a royal pain also someone (shmitty ) said replacing the rear oil seal isnt a big deal?? I thought (?theres the start of all my problems ME thinkin!!) I had to remove the engine and oil pan headers ect, to even get at the oil rear seal. I truly appreciate this advice guys, Thanx a LOT, I may have to just redoe my existing parts when engines out. I always wanted to up the compression to 11 to 1 for propane but since Im dual fuel ?? whats can I safely mill of the heads on my 1984 460 engine and still run it on 87 octane fuel? Also what would yo uuse for the thread repopaire i nthe cyclinder heads Timeserts uni serts? Thanx a LOT Guys you roick Mike

flexplate or flywheel that is zero balanced ...where do you buy one of these? Thanx Mike

I'd do thread repairs with helicoils, then put studs in the manifold bolt holes...naturally, use a good anti-seize compound on the nuts. It's much easier to free up a stuck nut than a bolt buried in the cylinder head. Maybe stainless hardware as well?

Just get the flywheel you have for that transmission, rebalanced to zero.

OH OK