Ok so I'm taking my car off the road for a week & 1/2 so my headers can be sent off to jet-hot for coating. So in the meantime the passenger head gasket has a leak so I'm tearing down the top of the motor *fun* . I have a friend who has an acquaintance that will do porting and polishing for cheap so......

The questions are, on a stock 87 305 bottom end with 62000miles

What should be done to the heads? (1.94 intake? 1.6 exhaust?)
I have equal length long tubes on the car with 1 5/8 tubes 2.5 collectors,
(Open the exhaust port that much?)
It has a Edelbrock performance intake with a 600cfm carb,
and mallory unlite distributor.

Also what cam kit would be good to match the heads?
she has a T-56 in her with 3.9 rear gears,
so I would like a good power band.

Also lower spark plug heat range right?

I know some have push 300hp out of there 305
witch I would like to have because it would push
this little 2700lbs car in to the low 13s high 12s .

I'm not going to full building this car up, I have a FD RX-7 that
is taking that role. This is just some money that
I decided to use because it will all be off and I
like going fast in my DDs


Thanks for all the input in advance, JR

 

If you can afford to do the 1.94/1.6 valves, go for it. Use back cut valves. The guy doing the porting probably knows his stuff, so I won't bother telling you what you should do to port them.

You're not changing CR ratio, so you probably don't need to change the plug heat range. Unless you're milling the heads, and using a thin gasket or something. Then maybe drop 1 heat range.

87- that's setup for a roller cam? In a 305, an LT1 cam is a good cheap replacement. A little low on the power band though. You've got a good tranny, and nice high gears, with that light car, you can go big on the cam, and go for the gold.
Let me know if you're doing a roller or flat tappet cam. I'm thinking it's a roller block, but i'm not 100% sure.

 

for your help (sonix)
and all let you know about the cam
after I tear down the motor tonight.

JR

 

1.94 with 1.6 valves will be a REALLY tight fit.... If I were in your shoes I would consider going with 1.94 and an exhaust of something closer to 1.55. Yes, do use the back cut valve stems, Manley makes them.

For a cam, which will be a roller cam, I'd say stay with near 220 @ .50 durations, with lifts of .480 to .550. Most of us use dual pattern cams to help make up for the smaller exhaust valves. You'll also need screw in rocker studs, and better valve springs with clearances milled to match the valve lift and avoid coil bind. Get roller tip rockers, or full rollers if you have the budget.

I'd also mill .010 off the heads just to get them flat again, and then use a .02x head gasket to get about 9.5:1 compression ratio. You may need to shop around for the right 350 gasket since a standard 305 head gasket may not clear those bigger valves.

Run a tap through all the head bolt holes in the block, wire wheel all the head bolts, and use teflon sealant goop on the clean bolt threads.

 

what is the casting number on your heads.?

 

the casting #'s are 4416. Which I hear have good potential right?

Thanks for you input mnorton, all see what the guy porting my heads says
and tell him what you guys said.

All be taking them in tomorrow so anyone else that has something to add
please do.


JR

 

If these heads are going on a stock bore 305 use 1.94x 1.50" valves.

 

You defenitly have some potential with those 416 heads. Those and the 081's are the best 305 heads to start with.