It would be great if you could get us some numbers from the block and the heads. I’m thinking that the pad on the front of the engine will have “TK” followed by a B, M, W, or X. The casting number for your heads will help a bit as well. Even though you indicated you want to keep the stock heads, you’ll need to have them checked out and re-worked with at least a good valve job and new seals. The following head casting numbers are pretty common and you probably have one of these three:

3993820, 1971-1984 oval port open chamber 402 and 454 – 113cc chambers
3999241, 1972 oval port open chamber 402 and 454 – 113cc chambers
6272292- 1970-1978 oval port open chamber -113 cc chambers

I know you said you’re on a “budget” – but you didn’t say how big the budget is. As Jerry mentioned, you could off the block on eBay for probably somewhere in the $300 - $600 and start fresh. You could have Pat build you a sweet engine – and know that you’ve got one of the best, or you can build this one yourself and learn a lot as you go! I’m old enough to be you dad (maybe grandfather) and I still like to “do-it-myself” however; I have learned that there are some things that are best done by professionals! While your engine is at the machine shop, buy a couple good books on big block Chevy engines and study them very carefully – there will be a test!

Machine shop is the first stop – have them inspect the block (sounds like this may already be underway) and perform the following:

1. Bore .030 over

2. Deck the block to make is nice and square

3. Line bore mains

4. Check the crank – turn .010 as necessary

5. Insert new cam bearings

6. Install all new freeze plugs (brass) and get all new threaded plugs. Have the machinist show you where they all are so you can make sure they’re installed as you put things back together.

7. Have you machinist check your rods, re-size as necessary and put in new ARP bolts. These bolts cost about $125 but are money well spent.

8. Have your machinist put your new pistons on the rods – KB160 series are fine for your build ($375 set). 1.765 compression height .180 dome with the stock 6.135 rods and stock 3.76 crank should get you in the 9.5:1ish area (after heads are surfaced) – use a .022 head gasket.

9. Buy your rings, bearings and gaskets from the machine shop. This helps to make sure you get the right ones! If you haven’t installed piston rings before, ask for help here – the machinist can put them on for you or he/she will show you how.

10. Have your heads done here too – If you can afford to go the roller cam route, go with a kit from Comp Cams – K11-413-8. This kit has the cam, lifters, springs, seals, retainers and locks. Your machinist can do a valve job, surface the heads and assemble with these new parts. The kit is about a $1,000. You also need the rocker arm kit that includes new roller tip rockers (1.72) as well as new balls, nuts and most importantly new pushrods that accommodate the roller lifters. This adds another $200 - but if you go the roller route it's critical to have the correct geometry here or you will ruin thing in a New York minute!

Now you get to take all this stuff home and put it together! Be sure and scrub the block with hot soapy water and dry with compressed air. Get a good engine stand – Harbor Freight or similar. Once the block is spotlessly clean – paint it with good engine enamel.

Go slow and ask lots of questions. If you don’t have all the tools you need, buy or borrow them. Torque wrench is a must as is a piston ring compressor, a good set of sockets and flat wrenches.

Up top, I’d use a Performer RPM and good ol’ 750 CFM Quadrajet.

Finish off with some good ceramic coated Hooker headers and you have 400 plus on tap!

I know this is a lot to digest – hopefully Pat will chime in as he really is the big block master. Listen to anything he tells you as he’s built fifty(or more!) to every -one I’ve built and like I said – he makes his living doing this while I just enjoy building one “now-and-again”..

Regards,
Glenn