marine 302

jmoorepghpa · 04-11-2007, 05:40 PM

I have a '76 mercruiser 888 which is a 302 block with 351w heads. Ford pulled the 351w heads off the assembly line and drilled them with 7/16 head bolt holes to fit the 302. The motor has what is basically a truck cam in it. The oem casting numbers are d5ae on the heads. They have the stud type adjustable rockers. Can I switch to a later model 302 head. I have heard that is good for a little more torque and the 302 heads flow better. If I use a later model 302 head that has the rocker studs will my rockers, pushrods and lifters that were used with the 351 head work? If I go to a 302 head that has the bolt down stamped rockers what lifters and pushrods should I get. The reason I'm going through all this is one of the oem d5ae heads cracked during the winter. Should I just get a rebuilt d5ae head, use the edelbrock washer kit to shim the head bolt holes down to 7/16 and get the other oem head rebuilt? Thanks for any help you can give me.

andy669 · 04-12-2007, 07:23 AM

You can switch to a later model 302 head with the factory pedestal rockers, but you will probably need a pushrod length different from what you have now. Your 76 will have a flat tappet cam and you should continue to run the same lifters that are in it, with that cam. The pushrods that you would get with the E7 heads would likely be too short with your HFT cam and lifters. An adjustable pushrod would be needed to figure out the correct length.

I dont know that the swap would be good for a power or torque increase, but it would get your boat up and running.

Andy

rwhite65 · 04-12-2007, 05:01 PM

lots of options. Is getting it up and running your only priority, or do you want a little better flowing head too?
Ryan

04-11-2007, 05:40 PM	#1
jmoorepghpa Registered Member Join Date: Apr 2007 Posts: 1	marine 302 I have a '76 mercruiser 888 which is a 302 block with 351w heads. Ford pulled the 351w heads off the assembly line and drilled them with 7/16 head bolt holes to fit the 302. The motor has what is basically a truck cam in it. The oem casting numbers are d5ae on the heads. They have the stud type adjustable rockers. Can I switch to a later model 302 head. I have heard that is good for a little more torque and the 302 heads flow better. If I use a later model 302 head that has the rocker studs will my rockers, pushrods and lifters that were used with the 351 head work? If I go to a 302 head that has the bolt down stamped rockers what lifters and pushrods should I get. The reason I'm going through all this is one of the oem d5ae heads cracked during the winter. Should I just get a rebuilt d5ae head, use the edelbrock washer kit to shim the head bolt holes down to 7/16 and get the other oem head rebuilt? Thanks for any help you can give me.

04-12-2007, 07:23 AM	#2
andy669 Registered Member Join Date: Jan 2001 Location: Moline Il Posts: 901	Re: marine 302 You can switch to a later model 302 head with the factory pedestal rockers, but you will probably need a pushrod length different from what you have now. Your 76 will have a flat tappet cam and you should continue to run the same lifters that are in it, with that cam. The pushrods that you would get with the E7 heads would likely be too short with your HFT cam and lifters. An adjustable pushrod would be needed to figure out the correct length. I dont know that the swap would be good for a power or torque increase, but it would get your boat up and running. Andy __________________ 88 coupe 91 LX NMRA Pure Street 5120

04-12-2007, 05:01 PM	#3
rwhite65 Ride Hard Join Date: Oct 2000 Location: Wyoming IL Posts: 1,094	Re: marine 302 lots of options. Is getting it up and running your only priority, or do you want a little better flowing head too? Ryan __________________ 65 Fastback 91 roller 306, H/C/I AOD-Bauman, PI Stallion, 4.10's and traction loc 04 Grand Cherokee Freedom Edition 79 Ford F-250 4x4 - Restored