Picked up a good project engine.

[Eggman63]

This might be a little long winded so I’ll apologize now. I have been looking for a small block for my 78 rat rod since the original 350 is seen better days. I found a local shop that restores corvettes and they had a Target Master 305 that has less than 10k on it. The original owner put it in his 64 vette back in 1980 and put the original engine in the crate it came in. Fast forward to now,the original owners son has inherited the vette and did a complete resto on it and needless to say he doesn’t need the 305. I bought it for $400 and it was even attached to a roll around engine cradle. My dilemma is,do i want to crack open this pretty much perfect condition engine to swap cams ,or should i just put it in and run it as is?

[Palf70Step]

I am a big fan of driving it first with used engines, before I put money into performance. Besides, drving the truck is more fun than working on them.

[Eggman63]

I agree. I have an edelbrock street master intake that’ll work great on a 305,the truck already has headers and full exhaust,new 350 turbo trans with a Jegs 2000 stall converter.

[mongocanfly]

welcome...
if it runs good then leave it alone...targetmaster was a generic low hp crate engine back in the day...unless your upgrading more parts than the cam ,then a cam swap isn't gonna do much good performance wise on that engine...unless you just want to make noise

[Eggman63]

I never knew they had a 305 Target Master! You’re right though,with headers and a 600 carb it should run halfway decent.

[LT7A]

You have a pretty unusual situation where you know the history of the engine and have access to the exact specifications. I would check with a couple of cam manufacturers and see what they recommend with your intake and exhaust and with the specs of the Targetmaster 305. If what they recommend is appreciably different than the stock specs on the TM 305 and seems like it would take advantage of your more open intake and exhaust then I wouldn't hesitate to put a new cam in before you put the motor in your truck.

[Eggman63]

I’m sure this thing has a puny cam in it. It does however have 416 casting cyl heads which do have 1.84/1.50 valves which aren’t killer by any means but are better than the alternative heads which have 7.? And 1.3 exhaust valves.

[Eggman63]

So i have decided to crack this engine open. Going to install a summit 1787 cam,204/204-.427/.427 on a 110 lsa,valve springs and seals,1.5 forged roller tip rockers,Streetmaster intake,1406 carb,HEI,jegs 2000-2300 converter,Turbo 350,oh and full length headers with full 2.5’ exhaust. This should be fun!

[LT7A]

It's been a year Eggman plus a couple months. How did it come out?

[MikeB]

Originally Posted by Eggman63

Going to install a summit 1787 cam, 204/204-.427/.427 on a 110 lsa,valve springs and seals,1.5 forged roller tip rockers,Streetmaster intake,1406 carb,HEI,jegs 2000-2300 converter,Turbo 350,oh and full length headers with full 2.5’ exhaust. This should be fun!

The key to choosing a cam for an engine with stock compression (probably 8.0:1 or less) is making sure the intake valve doesn't close too much later on the compression stroke than with a stock cam. 204/204 with a 110 LSA isn't optimal, but probably won't kill the compression too much. I'd prefer a 204/204 cam with a 108 or even 106 LSA to get the intake valve closed sooner.

Back in the 1980s, the 305 HO used in the Z28 had a 195/202 cam with .390"/.410" lift, but I can't remember the LSA. And those engines may have had better heads and higher compression than your Targetmaster.

I suggest googling "Chevy 305 HO" to learn more about those engines.

Here's something to start: https://www.thirdgen.org/forums/tech...een-305-a.html

Just found these little known Comp cams with 108 LSA:

https://www.summitracing.com/parts/c...make/chevrolet

https://www.summitracing.com/parts/c...make/chevrolet

[LT7A]

Hey Mike, thanks for jumping in. I'm interested to look at the links you posted. I believe the heads that Eggman has are the same that are used on the LE9 305. And I think the compression ratio nets out between 9.2 and 9.5. I think that is why the electronic spark control came on the scene to retard the timing if the little motor started to ping.