small block heads
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Senior User
Joined: Apr 2003
Posts: 167
Likes: 2
From: detroit michigan
small block heads
hello
i have a 1992 ford e250 van with a 351w in it. the truck has a blown head gasket on the left bank. engine has 150000 miles on it. it uses no oil and has good oil pressure and runs quiet.
the heads on this engine have the air pipe in exaust manifold
(1 1inch pipe) i want to replace the heads with very low mile heads that i found on a parts locator. the heads that i found are for a 302 with air in the heads (pipe on back of heads)
i know that the head bolt holes need to be drilled to 1/2 for the 351w. and the ports on the back of the heads need to be blocked off and use the stock 351w exaust manifolds to retain proper smog equipment. is it possible to drill the head bolt holes my self or should i take them to some shop to have them done?
the heads that i`am getting have the orignal rockers form the 15000 mile motor. are these rockers the same as 351w rockers?
if so i will purchase new push rods. i`am also changing the cam,lifters,timing chain,gears,oil pan,rear main seal,water pump,distributor gear (because of new cam)cam bearings,and all gaskets and seals on engine. this truck is totaly stock 1992.
i also want to know if i can put a better cam in without having to change valve springs or stock rocker arms. it is not a drag van so i`am not looking monster lift just something to give it a little bit more power . if i have to change rockers or springs then i will just get a stock cam and lifters i think this 1992 351w has a roller cam in it but i`am not sure. if i put a little bigger cam in will the pistons have to be fly cut for clearance? if so it is not worth it to me. the van is still driving so i`am not sure if the pistons are flat top or dished. if it is possible to put a bigger cam in the engine without changing anything else will it affect the ecm (check engine light) also what cam would you recomend for a roller motor? (brand and part number if you have it) will what i`am trying to do work? sorry this is so long winded but i think it is better to ask questions before i get into this project and buying parts that will not work. thanks for your time
i have a 1992 ford e250 van with a 351w in it. the truck has a blown head gasket on the left bank. engine has 150000 miles on it. it uses no oil and has good oil pressure and runs quiet.
the heads on this engine have the air pipe in exaust manifold
(1 1inch pipe) i want to replace the heads with very low mile heads that i found on a parts locator. the heads that i found are for a 302 with air in the heads (pipe on back of heads)
i know that the head bolt holes need to be drilled to 1/2 for the 351w. and the ports on the back of the heads need to be blocked off and use the stock 351w exaust manifolds to retain proper smog equipment. is it possible to drill the head bolt holes my self or should i take them to some shop to have them done?
the heads that i`am getting have the orignal rockers form the 15000 mile motor. are these rockers the same as 351w rockers?
if so i will purchase new push rods. i`am also changing the cam,lifters,timing chain,gears,oil pan,rear main seal,water pump,distributor gear (because of new cam)cam bearings,and all gaskets and seals on engine. this truck is totaly stock 1992.
i also want to know if i can put a better cam in without having to change valve springs or stock rocker arms. it is not a drag van so i`am not looking monster lift just something to give it a little bit more power . if i have to change rockers or springs then i will just get a stock cam and lifters i think this 1992 351w has a roller cam in it but i`am not sure. if i put a little bigger cam in will the pistons have to be fly cut for clearance? if so it is not worth it to me. the van is still driving so i`am not sure if the pistons are flat top or dished. if it is possible to put a bigger cam in the engine without changing anything else will it affect the ecm (check engine light) also what cam would you recomend for a roller motor? (brand and part number if you have it) will what i`am trying to do work? sorry this is so long winded but i think it is better to ask questions before i get into this project and buying parts that will not work. thanks for your time
Cargo Master
Joined: Jun 2001
Posts: 2,571
Likes: 22
From: Oxford, Indiana
small block heads
Have a machine shop redrill the bolt holes to 1/2" and use new head bolts. It's virtually impossible to get them bored on center with a hand drill or even a drill press. If they are off even a little, the bolts may bind and give you a false torque reading. Can you say "blown head gasket all over again"? The rockers should be the same assuming that the new heads are post 1977. Your pistons are dished. Check into a Comp Cams part# 35-255-5. It's a high torque grind designed specifically for use with speed density EFI computers. It's a nice cam. You have to be extremely careful swapping cams in a speed density EFI engine. It's very easy to end up losing driveability or fuel mileage with the wrong choice. This cam has proven itself and I've not run across anyone who was at all dissatisfied with it's power.
