Best mild cam for a stock olds 403...

[olds307 and 403]

You can still get the replacement pistons. Just figure out your head cc and where you want to go with this build. Take it to a shop, you will need the pistons pressed on the rods anyways. Then you can hone the block and they should be able mock up the new pistons and how much will need decked on the block. I bet a 0 decked block will give you 8 to 1. Decking gives better quench, helpful if you increase the compression ratio later with different heads. How does the crank look? It is up to you how you want this engine built. My 8.3 to 1 403 has fried two transmissions and just blew up my 7.5" rear. I think mid 9's in the 1/8 will be easy if something else doesn't blow.

 

[dogsht]

As mentioned the machine shop can mock it up and find out how far they would be down the hole. Mill the heads enough to be square then get the rest from decking the block to get zero deck. If you find good 350 heads that would still always be ideal.

 

[brian_wms]

Found some 68 olds 350 heads hadn't purchase yet the guy wants $350 and they have to be redone. How much more hp will i gain going this route? Is the head swap really worth the trouble for a weekend driver?

 

[DoubleV]

Yes the 350 heads would be worth it, but $350 is a ripoff for a set of sbo heads that need to be redone IMO. I would'nt offer more than about $200 at most. I've seen 350 head cores go for as little as $100, and that's for the good 68-72 ones.

 

[brian_wms]

yes that is very high for heads that need work. Guess i'll leave it stock, not trying to race anyway. Just want a good weekend cruiser.

 

[dogsht]

Why don't you offer him $200. All he can do is say no. It's a ripple affect decision that leaves a lot of streetable power on the table & once your past it you don't want to spend twice do work twice to come back.

 

[brian_wms]

The guy sold the 68 heads but i've located another 72 engine with 7a heads for 300.
How much is involved with this swap. Can some one give me a list of things i have to do?
What kind of hp numbers will I see, just a rough estimate?

 

[ZZ4CutlaSS]

If you find a nice set of 68-72 sbo heads and have them drilled to except 1/2 head bolts. And also install bigger 2.02 and 1.6 valves even with stock pistons you will have a screamer. Dont go to big on the cam RV cam is perfect. I would also get some harland sharp pedistal mount 1.6 rockers and will have a bad *ss torque monster.

 

[dogsht]

If he gets the heads for what about 9.5-1 with thin gaskets and gets the bigger valves (bowl work & competition valve job that should accompany it) & 1.6 rockers as you say why shouldn't he get a cam to take full advantage of it and have a little milder Olds equivalent to your ZZ4?

With headers, carb & advance curve timing adjustments 300+HP would be do-able with tuning. An Edelbrock Performer RPM intake manifold would take that out a little further. Edelbrock made 397HP & 400TQ with their Olds 350 rpm kit but that included their heads & pro tuning. Here is one of Lunati's cam kits which includes the lifters & springs http://www.lunatipower.com/Product.aspx?id=2349&gid=297 and here is the adjustable vacuum advance curve kit for timing adjustments http://www.summitracing.com/parts/CRN-99600-1/ It would require pump premium but setup right would still work with power steering & brakes. You would need jets & hangers for your carberator also and maybe more changes if its still a ccc carb setup dunno off the top of my head. Might need the distributor out of the donor engine you are looking at.