HEADS

[garylt]

NEED TO KNOW IF YOU CAN PUT 1996 LT4 HEADS ON A 1986E.

 

[Edmond]

Nope, won't work.

 

[garylt]

heads

thanks for the help. what aluminum head would be good for a 1986e. garylt

 

[grumpyvette]

http://www.airflowresearch.com/

AFR 180cc SBC Street Cylinder Head

The Small Port, High Velocity Torque Monster

The AFR Emissions Legal (versions from 1969-94 with heat riser, CARB EO #D-250-2), 180cc intake port small block Chevy cylinder heads are available in your choice of straight, or L98 angle plug versions. These heads feature a 74cc or 68cc combustion chamber with a 64cc exhaust port and a 3/4” thick head deck (ideal for nitrous or
blower applications.) The 68cc chambers are designed for flat top or dished pistons; domed
pistons will require additional machining. Standard valves are 2.020 intake and 1.600 exhaust with AFR’s hardened ductile iron interlocking valve seats. The exceptional flow characteristics, ideal operating range of idle to 5500 rpm (higher rpm ranges possible depending on combination of parts), 23º valve angle, and standard valve spacing make this the perfect street head for 327 cid to 350 cid engines from 1955-86. Also available for 1987 to present engines with center bolt valve covers and 2 center intake bolts at 72º angle. No special parts are required. Vortec style head available too.
Note:

Hydraulic roller cams typically experience valve float at 5800-6000 rpm because of their fast ramp rates. AFR suggest you upgrade your springs to AFR part #8032, 1.530 O.D. with higher spring pressures and use our Patented “Hydra Rev Kit” to reduce chances of valve float associated with rpm 6000 or higher

 

[77-85]

thanks for the help. what aluminum head would be good for a 1986e. garylt

Although I don't want to recommend any particular brand of aluminum head, I will tell you what I did on my 85 which I believe has the same basic engine configuration as your iron head 86E does.

First of all you need to remember that your stock heads incorporate an EGR passage in the head itself which is fed through the TPI baseplate to the EGR valve, and you also need to consider that your engine had flat top pistons and 76cc heads. All later vettes have the aluminum heads without EGR passages (EGR is from manifold to the TPI baseplate), and I believe that the later vette heads have 58cc combustion chambers and dished pistons to compensate for the much smaller combustion chamber.

I purchased some 64cc aluminum Edelbrock heads with the EGR passage in the heads, and I continued to use flat top pistons. The switch from a 76cc iron head to a 64cc aluminum head bumped my compression ratio from 9.0:1 to about 10.0:1. I just make sure I use premium fuel all the time and I do not have any issues with pinging. Note that where I live 94 octane gas is easy to get, if you live in an area where you can only get 91 or 92 octane fuel, you may want to consider a head with 70 cc combustion chambers.

Also note that most aftermaket heads have larger valves and intake ports which may reduce your low end torque slightly. In my case I also put in a better cam and a high flow baseplate and runners at the same time so the new heads worked out quite nicely.

There are many choices in terms of aluminum head manufactureers (AFR, and GMPP are two examples), but as long as you remember you need heads with an EGR passage you should be OK.

 

[garylt]

THANKS FOR ALL THE INFO, garylt.

 

[Edmond]

I just got the Super Chevy magazine today that did a piece on AFR heads. Those are some nice looking heads! Don't know how much they cost but I think the Edelbrocks were somewhere in the $1100 neighborhood fully assembled.

69MyWay had the Edelbrocks on his old C4 that he had built up.

 

[Inertia 500]

Did your '85 have an EGR pipe running from the exhaust manifold on the passenger side to the TPI baseplate? My '86 with iron heads does. Does that mean that it does not have internal EGR porting in the heads?