Just thought I would run this combo by you guys and see where I can improve on. This is actually going into a 80 El Camino. Just trying to wake it up a little it’s old and tired. Engine is a 305 LG4 with a 700R4 and prob like 3.08 gears open diff. I did a compression check and the bottom end seems to be in decent shape. It’s in need of a cam swap pretty bad. So nothing to fancy and pricy because it is the daily driver for now and I can live with it being a 305 until I can find and build a 350. The truck was in bad shape when I got it so it now has:
4160 Holley 600 Vs
A edelbrock performer intake I had laying around
Pair of 2451 hokker headers (full length 1 5/8 primarys)
Full dual exhaust through poor man mufflers (glass packs )
New cap/wires/plugs
It runs a lot smoother now. So I was thinking its time to try and take advantage of the better air flow it has available. So here is the idea I had when doing the cam swap. Take the heads off I can clean/port/polish and take them to have a 3 angle valve job done. Worth it? It has around 8.5 compression so was thinking about going with a 1094 .015 head gasket to maybe raise it a bit. Would it be worth getting the heads milled down a little .010 or so? The cams I am looking at are:
1103 from summit Duration @ 50 214/224 Lift .442/.465
1104 from summit Duration @ 50 224/224 Lift .465/.465
Was also thinking of some roller tipped rockers but didn’t know if the heads could handle 1.6 or just stick with 1.5 Because with 1.6 on .465 lift should make it around .496. So if it could handle that amount of lift without major head work but with stiffer springs that’s what I’m shooting for if not I’ll stick with 1.5 but still need to upgrade my springs. Looking at cca-981-16.
Price I’m looking at now is cam kit $70, Head gasket $20 ea., timing chain set $20, cam change gasket set $25, valve spring $60-100. Roller tip rockers $90. = around 315 + machine work. Thanks a lot any info is appreciated.

 

Depends upon what heads are on it whether or not the P&P will help. I believe a lot of those late 70's/early 80's 305's got 1.72" intake valves. Too small to get much help from larger cam or P&P.

Summit cams are pretty lame. Poor idle, poor mid-range, peaky power. A more modern grind like an XE262 would be much, much better and well worth the extra $'s.

A 1094 head gasket would maintain compression, because the factory used steel shim gaskets. The cam suggestion above would be better money spent than milling the heads.

Stick with 1.5 rockers. You're on the edge lift-wise without cutting the guides down (not a bad idea, and add positive-type stem seals while you're at it).

 

Thanks. The xe262 does look alot better. And the 1.5 rockers. So would those springs I listed be fine? I'll try and pull a valve cover tomorrow and see what heads are on it thanks.

 

starting in 80 the LG4 should have 4416 heads which are good to port and play around with, as thousands of ppl have done and have had good results,

1.84 valves if they are the 4416 heads


80 was also the first year for the passenger side dip stick in the block and thus different oil pan
i really highly recommend a better axle ratio for what you are looking at doing

you need to decide upon what rpm range you will be most running the car at and when you want its power to be put out(RPM range again)

in order to know what cam and stall and so on

but then it takes you back to the axle ratio problem again

if it were mine id be getting a better ratio


and getting poly(or something good like that) chassis suspension bushings and better rear springs,

and double checking the braking system condition- if not making improvements to it,

and boxing in control arms,


and such first

just my $.02


good luck

 

Yeah, I know I need a diff ratio. thought about atleast 3.42 or 3.73. But the rear will be on of the last upgrades because as of right now the tire turns and gets it down the road, sad but true. Is the rearend the same as in 3rd gens. Also would it be better/more cost efficent to convert that rear to a posi unit of buy a whole rear and swap it? And from searching around i have seen 4thgen rears in 3rdgens would this possibly work for me? Be nice to have rear disc brakes also. The rpm range i was shooting for was just a good streetable 1,500-5000 or so. As for as the suspension its the next to get undated. Thanks for the help

 

Any more info regaurding the rearends?